Shed roof - felt or rubber

[Waitforme]

I need to fix my leaking shed roof , it’s a sloped roof , not like an upturned V.
I’m wondering whether to felt it or use a rubber membrane on it ?
Any opinions ?

[Waitforme]

Thanks for the replies.
If I’m going to have to re cover it I’m swaying towards the rubber as it goes on in one sheet.

But …. The felt that is on isn’t torn it’s just the 2 seams that are leaking as I never used any bitumen or sealant when I refelted it a few years ago, so I’m wondering whether to just lift the felt, put down some kind of sealant and re lay the felt that is on it.