you can, but it's highly discouraged, if your run gets called out for cheating/splicing, without sound you're gonna have a harder time.

I'm on ps4 but I can't record over 1 hour. So I'll stream and record with my phone but there is no sound ...

You might want to get a capture card if the internal recording of the ps4 isn't enough.

There are plenty of capture card options that fall way below the €200 mark

The PS4 has a livestream feature. Use that. You stream as much as you want. If you are gonna stream using Twitch, make sure that you enabled saving your broadcasts when you are done with them.