A Torah commandment
"You shall eat and be satisfied, and bless the L-rd your G-d for the good land He gave you" (Deuteronomy 8:10). Birkat Hamazon is said after eating bread; the full text is in our Siddur.
The Edot HaMizrach nusach
Maran stressed not changing from one's ancestral nusach, and that Sephardim pray in the Sephardic order. The Chida wrote that the Sephardic prayer rises through all twelve gates.
The Siddur on this site
Shacharit, Mincha, Arvit, Birkat Hamazon, Al HaMichya, Ashrei and Birkat HaLevana — with text-size controls and night mode. This article is for learning, not a halachic ruling; for practical questions, ask a qualified rabbi.
Sources
דברים ח, י — ואכלת ושבעת וברכת
Birkat Hamazon text · Sephardic Siddur online · Sephardic prayer