SRAM 1X Chainset… dust cap? crank cap?

Morning

My commuting/CX is a SRAM 1X and I’ve noticed that the cap that covers the centre of the chainset on the drive side is missing – I can see bare threads and it doesn’t look too great (although it runs ok)

Question is – what do I look for in order to buy the replacement? I’ve looked at the SRAM manuals and searched for chainset cap/spares crank cap/spares 1x spares etc and can’t see to find it

Had a similar problem with an FSA BB30 chainset a few years ago where the same thing happened and it took a few weeks for the LBS to find it in spares.

I can do most things mechanic-wise (to a standard) so ok fitting it even if I have to buy a tool to do it but I’ve no idea what to buy!