When you apply for a new credit card, you need to provide income documents.

If you already have a credit limit from CIMB Bank (conventional banking), you may have to "convert" from CIMB to CIMB Islamic. Talk to CIMB Card Centre. Not easy to have 2 credit lines, each from CIMB Bank (shared for all CIMB CC) and CIMB Islamic Bank (shared for all CIMB Islamic CC).

I hold TWE and e-card with >200k limit but they refused to grant me Islamic facility multiple times. Couldn't even get the Platinum card lol. The only option they told me was to pledge FD but their rates are so bad that it wasn't worth it at all.