I had done a speedrun for 20 flags endless it is about 3 days since im curious what would be an avarege time in which i will know if im aproved?

Sometimes it takes time. I'm not a moderator or anything but in some other games I've submitted to it takes like a month. I submitted something here last week and the guy got back to me about it within less than a week so I would just give it another few days. they will probably have it looked at by then if I had to guess.