Hi Youngbelize. This happened to my brother and his P38 in UK.
There is an emergency key access code (EKA code) of (I think) 4 numbers that gave unlock when his remote locked him out because his remote battery was flat.
In his case the code was originally with his documents but there may be a metallic tab on the key ring with the code stamped on it.
If you can't find the code I think it can be found from one of the electronic boxes in the car (when you get in...)
Sorry it's a bit vague; perhaps someone might flesh this out a little more.
(I noticed that the process is similar to our MGF/TFs. Is there a P38 forum you can ask instead?)
There seems to be a paid-for service that looks up EKA/radio codes etc but this forum won't let me copy the link to you.
Google 'Rover eka code' OR https://remotekey.co.uk/land-rover/land-rover-eka-code-emergency-key-access-code/
OR email: [email protected]
(ps why can't I delete/change the post and why does it sometimes delete the post when I try to type a semi-colon, for example :-(?. Is it my keyboard that's the cause...? Strange things seem to be happening to me with this new format...)