It's 1294 from Girls' Frontline again. (Miley is AK-12's unofficial Korean nickname, derived from the Korean keyboard layout. Similarly, Angusa is AN-94's nickname of sorts, derived from a reading of AN94.)
A Book About AK-12 (and AN-94) Getting Attracted is a completed manhwa by Tsuka, first published in 2019. It blends girls' love. You can read all 1 available chapters of A Book About AK-12 (and AN-94) Getting Attracted online for free on MangaPulse; the newest is Chapter ?, added 2025-12-17. The series is finished, so you can read it from start to end in one go.