@Betty not ADHD but in a similar situation where doing large sets often doesn’t work for me!
greasing the groove is the fitness people term for doing single reps or very short sets (less than five) many times throughout the day rather than doing one long workout — an example would be installing a pullup bar and doing a rep every time you walk through that doorway or doing a couple squats every time you get up from your computer, whatever you think can comfortably work into your routine