If the metal isn’t broken off the fob itself then you can just swap guts or half the shell and it will work fine. Did that for my wife’s older Lexus. Then when it fell apart completely I went to a local key shop and got a whole new key, swapped parts and cut for $40.

Here is the one I used. May have parts for the one you need. UTSAUTO Replacement For Lexus Key... https://www.amazon.com/dp/B078SPXJPJ?ref=ppx_pop_mob_ap_share