Verses with the word supplication in the New Testament (3 verses):

Acts 1:14
These all continued with one accord in prayer and supplication, with the women, and Mary the mother of Jesus, and with his brethren.

Ephesians 6:18
Praying always with all prayer and supplication in the Spirit, and watching thereunto with all perseverance and supplication for all saints;

Philippians 4:6
Be careful for nothing; but in every thing by prayer and supplication with thanksgiving let your requests be made known unto God.