Hello and welcome to AA!
3 weeks is still a very short time to have had them and expect full bonding.
So no worries there!
I'm not sure but I think it's also said when you've got more than 1 bird it's harder to bond with them because they're probably going to bond more with each other, but it shouldn't be impossible!
You could hang a bowl in their cage (preferably next to a perch for easy acces) which you can also easilly access without entering the cage and everytime you spend time with them, even if it's for a few minutes, put a treat (like a very small piece of millet) inside the bowl.
The idea is that they get curious, check it out, and associate you with good things like treats.
If they don't run away when you're near or even go to the bowl when you put a treat inside, they are getting less frightened by you.
The next thing I did with my budgie (he was a solo bird so that might be different) was open his cage, put a spring/stalk of millet inside and just held it there.
Note: I took the whole sprig/stalk of millet, so not just a little bit, and just hold it there and let him come to me and eat from the millet.
My budgie was deathly afraid of hands so he knew (because he saw) that I was holding the millet but because my hand was far away from him, he was okay with it and eating happily.
Try not to make sudden movements while doing this.
I did this for quite a while with him to keep associating me with good things and also kept working with him on his pace.
After a while (maybe 1-2 month-ish?) I could offer him more smaller pieces of millet, with my hands each time a bit closer to him, and after a while he was sitting on my hand(s) while eating from the millet.
It's important to let your birds set the pace while bonding/training with them.
My budgie was also a loafer but I've only seen him doing while sitting on perches
Your budgies are beautiful, very nice colours!
