I am using Bingx and in futures I can change/move the SL but in spot trading I cant change Stop Loss..
I never used Bingx but if they are showing a feature of editing SL in the future but not on the spot trading page, then it means they don't support this feature on the spot. Your sole request might not convince them to add this feature, but they might consider it also (as there is still that possibility), besides contacting them on support to see if they have a suggestion box page on their site, or visit there telegram if they are giving replying to you, then you can share your suggestion there.
But keep in mind that, exchanges don't take suggestions that seriously, I never used stop loss in Spot trading, because if I have some limit in my mind, I simply set the sell limit, instead of SL limit. I mostly use Binance. And we can edit the SL in Binance AFAIK.