Is it possible pairing Mi Band 4/Mi Band 5 without app (i.e via Settings/Bluetooth/Add Device)?

As far as I know it doesn't work that way. If someone you know has a better Android phone, you can borrow it to install the Mi Fit, and then setup the connection to your Mi Band. Once you've the time and everything synced. You can disconnected the band from the app, and use your band standalone.

But, please note that the Mi Band has limited memory to store all the data.

Thanks for your reply.
I forgot to mention that I wanna use Mi Band 4/ Mi Band 5 as music controller for my (music) phone & earbuds TWS. That's why I can't use other phone for pairing & playing songs.
Or do you have any sugestions what kind devices should I use to control music on my phone via bluetooth with easy pairing and doesn't require any apps to pair?
Regards

Sorry, I'm not too sure about this. The phone OS seems to be a bit too outdated. Just wish that you have earbuds that able to control music playback :)