Do not pray publicly
Intro
The scripture is always true and people make mistakes when they don't trust the scripture and follow it. One such example is praying publicly. Some people pray publicly by mistake others do it to teach others how to pray and then some do it because they don't know the scripture or they have been influenced by churchianity prayer meetings.
The best scripture maybe to support prayer meetings in Mt 18:19-20. But do you know that its not a tare or a wolf in sheep clothing that you are praying with? He might turn your prayer request into a curse request, to curse you on behalf of Satan. Don't be surprised if you find Satan working in the church and in the prayer meeting. Isn't that the best way to get to people. To listen to their personal prayers and turn them into curse requests?
Prayer meeting can be seen in Acts 12:5-17. So it did exist in the bible. But as I said make sure you are praying with friends and that you agree with each other what you pray about.
Praying in public though should be something else than a prayer meeting. Unfortunately it might not be that today because churches are public buildings and not the kind of underground private persecuted churches of the first century AD. Churches are tax exempt status buildings run by a hireling.
Praying in public is absolutely true if you pray in a public youtube video for example. Its even recorded and can be replayed by anyone. That is public because anyone can see it and they don't have to be in some church even or congregation. They don't have to be saved and they don't have to know you and you don't know who they are that see you praying. So that is public. We are not to pray in public (Mt 6:5-6).
Scripture
(Matthew 6:5-15 [KJV])
[5] And when thou prayest, thou shalt not be as the hypocrites are: for they love to pray standing in the synagogues and in the corners of the streets, that they may be seen of men. Verily I say unto you, They have their reward.
[6] But thou, when thou prayest, enter into thy closet, and when thou hast shut thy door, pray to thy Father which is in secret; and thy Father which seeth in secret shall reward thee openly.
[7] But when ye pray, use not vain repetitions, as the heathen do: for they think that they shall be heard for their much speaking.
[8] Be not ye therefore like unto them: for your Father knoweth what things ye have need of, before ye ask him.
[9] After this manner therefore pray ye: Our Father which art in heaven, Hallowed be thy name.
[10] Thy kingdom come. Thy will be done in earth, as it is in heaven.
[11] Give us this day our daily bread.
[12] And forgive us our debts, as we forgive our debtors.
[13] And lead us not into temptation, but deliver us from evil: For thine is the kingdom, and the power, and the glory, for ever. Amen.
[14] For if ye forgive men their trespasses, your heavenly Father will also forgive you:
[15] But if ye forgive not men their trespasses, neither will your Father forgive your trespasses.
(Matthew 18:19-20 [KJV])
[19] Again I say unto you, That if two of you shall agree on earth as touching any thing that they shall ask, it shall be done for them of my Father which is in heaven.
[20] For where two or three are gathered together in my name, there am I in the midst of them.
(Acts 12:5-17 [KJV])
[5] Peter therefore was kept in prison: but prayer was made without ceasing of the church unto God for him.
[6] And when Herod would have brought him forth, the same night Peter was sleeping between two soldiers, bound with two chains: and the keepers before the door kept the prison.
[7] And, behold, the angel of the Lord came upon him, and a light shined in the prison: and he smote Peter on the side, and raised him up, saying, Arise up quickly. And his chains fell off from his hands.
[8] And the angel said unto him, Gird thyself, and bind on thy sandals. And so he did. And he saith unto him, Cast thy garment about thee, and follow me.
[9] And he went out, and followed him; and wist not that it was true which was done by the angel; but thought he saw a vision.
[10] When they were past the first and the second ward, they came unto the iron gate that leadeth unto the city; which opened to them of his own accord: and they went out, and passed on through one street; and forthwith the angel departed from him.
[11] And when Peter was come to himself, he said, Now I know of a surety, that the Lord hath sent his angel, and hath delivered me out of the hand of Herod, and from all the expectation of the people of the Jews.
[12] And when he had considered the thing, he came to the house of Mary the mother of John, whose surname was Mark; where many were gathered together praying.
[13] And as Peter knocked at the door of the gate, a damsel came to hearken, named Rhoda.
[14] And when she knew Peter’s voice, she opened not the gate for gladness, but ran in, and told how Peter stood before the gate.
[15] And they said unto her, Thou art mad. But she constantly affirmed that it was even so. Then said they, It is his angel.
[16] But Peter continued knocking: and when they had opened the door, and saw him, they were astonished.
[17] But he, beckoning unto them with the hand to hold their peace, declared unto them how the Lord had brought him out of the prison. And he said, Go shew these things unto James, and to the brethren. And he departed, and went into another place.