Siman 120
Presented here for study, not as a practical ruling. The Shulchan Aruch rules by Sephardi custom, the Rema's glosses by Ashkenazi custom, and the Kitzur follows Ashkenazi custom. For a practical question, ask your rabbi.
א אוֹמְרִים רְצֵה בְּכָל הַתְּפִלּוֹת, וּדְלֹא כְּאוֹתָם שֶׁנּוֹהֲגִים שֶׁלֹּא לְאָמְרוֹ בְּמִנְחָה.
1 That It Is Proper To Say "R'tzei" in Every [Amidah] Prayer. Containing 1 S'if: We say "R'tzei" in all the [Amidah] prayers; and this is not like those who have a custom to not say it in the afternoon [Amidah] prayer.