The CICS/RACF manual documents how a certificate is associated to a user id:
Associating a RACF user ID with a certificate
You can associate a certificate with a RACF user ID in two ways:
The RACF RADCERT command converted, is equivalent to a:
TSS ADD(xxxxx) DIGICERT(digicert) DCDSN('datasetname') TRUST
xxxxx - is the owning acid
digicert - is the user defined DIGICERT name.
dataset - is the dataset that contains the certificate.