Taming budgies outside the cage

I have a question about taming budgies. I ve 4 budgies for about 3months. Now they have started eating from my hand and sit on my hand inside the cage but only when food is in my hand. If no food they won't come and sit on my hand. Outside the cage story is totally different. Outside the cage they won't come near me whatever treat is in my hand. I saw so many people showing their budgies coming to them sitting on shoulders but when mine will do the same. Please help. Thanks

It's going to be hard. Worth it, but hard!

I have two, who came to me already hand-fed, and I've been home/on lockdown with them EVERY DAY since they came home 4 months ago - meaning I've talked to them and worked with them almost constantly.

But because there are two, I am only *just* getting to the point where one of them will sit on my shoulder. And he will only do it long enough eat his treat, then flies off. The other one will "come" to me from across the room - but again, only when he wants a treat.
Sometimes they still decide to run away from me when it's time to go back into their cage, and they are fully flighted so.. that's a pain

It's often easier to tame a single budgie, because they are social and they want company. If there is no other bird and you have shown them you are trust worthy, they will come to you for that company.
If there is another bird they are happier, because they have friends who understand them perfectly! But.... you aren't naturally one of them Since you have four.. they already have plenty of friends.

To get there:

Normally after you get them eating from your hand, you start holding the treat back a bit so that they have to step on your hand/finger to reach it.
If this isn't working for you, you can try it with a dowel/perch. Some birds are more comfortable that way.
Hold the treat so they have to step on the dowel to get to it, and then when they reliably step on that dowel you can work on moving them closer to you/outside of the cage.

Once they are reliably perching on your finger or a dowel perch and letting you remove them from the cage, you should have an easier time of getting them to use the perch/your finger to go back in.

The entire goal is just proving to them that you are not a scary monster who wants to eat them. The only way to do this is to be around them and not scare them. Sit close, talk to them, have your hands on or in the cage, and lots of treats... everything comes in baby steps though, and if one bird is wary its going to make the other three wary as well. Don't chase or grab them when they are out, back off if they seem nervous, have treats when they do let you close, and they should learn overtime that you approaching is not a bad thing.

One of mine got scared when I accidentally let him see a new toy I was unwrapping -_- He freaked out flew out of the cage, then started flying around the room and wouldn't let me come near him even with a treat. I had to stay calm and talk to him softly from across the room, and literally approach him with both hands up in the "I'm unarmed" posture. Once he was on my finger I still had to keep my other hand up and in his sight until we got back to the cage. I don't grab him unless I need to check him for an injury, but he was so worked up he just couldn't trust.

I'll be honest - from everything I've learned.. you very well may not ever get four budgies to be tame/friendly enough to come sit on your shoulder. But I am confident that you can get them to trust you enough to let you approach them outside of the cage, and get them to step on a perch.

Edit: I've found with mine that I made the most progress when I actually stopped trying too hard. You have to be relaxed to help them relax. I tried and try to get them to "come" using clicker training, but they wouldn't do it from more than 6 inches away. Then one weekend I was just playing a game on my computer and letting them do their own thing on their perch for a couple of hours when one of them suddenly flew over and landed on my head for a second. It's gotta be their idea