1992 525i Keyless Entry Help

[Broombroom]

As title

Picked up a brand spankin old E34 today but the single button fob is missing the single button.
I checked the mirror and it doesn't have an IR receiver so I'm wondering where it could be?
I've already ordered a replacement key, so I need help discerning whatever it is I'm supposed to be doing once I get it?

As a side question; can I program a multi button fob to this car? With boot unlock, windows up/down, etc?

Thanks if anyone helps

[shogun]

Are you sure that fob is a remote one? With a single button it could be just a normal key fob with light button.
Normal keys are shown on page 7, next pages the remote control "switchblade" https://dokumen.tips/documents/bmw-e...al.html?page=8
retrofit http://bmwe32.masscom.net/johan/remo...e_locking.html
aftermarket http://www.bmwe34.net/E34main/Upgrade/KeylessEntry.htm
https://www.youtube.com/watch?v=OFk5Yln0DqI