Migrate config from 3600 to i4600

If I use the platform-migrate option I get the below error:

Installing full UCS (12.1.0) data, excluding license file.
The hostname is set to apl-amb-bigip01.x
Extracting manifest: /var/local/ucs/BigIP01.LatestConfig230617.ucs
Product : BIG-IP
Platform: UCS   : Mercury
          System: C115
Version : UCS   : 12.1.0
          System: 12.1.2
Edition : Final
Hostname: apl-amb-bigip01.x
Installing --full-- configuration on host apl-amb-bigip01.x
Installing configuration...
ERROR: Module apm is invalid for platform-migrate mode. Only LTM and GTM are supported.
WARNING:
    This system's device certificate uses a key size that is considered insecure.
    It is strongly recommended that you use a certificate with a key size of at least 2048 bits.
ATTENTION REQUIRED:
   Your previous configuration files have been archived, as listed
   below. If you customized any settings in these files before
   upgrading, you will need to manually restore those changes by
   using the Configuration utility or Traffic Management Shell (tmsh).
   Archiving /config/wa/pvsystem.conf.12.1.0
   Archiving /config/wa/globalfragment.xml.12.1.0
   Archiving /config/wa/pvsystem.dtd.12.1.0
Post-processing...
usermod: no changes
Error detected.  Skipping final load.
WARNING: There were one or more errors detected during installation.
         Check the error messages and take the proper actions if needed.
ERROR: UCS installation failed.
Operation aborted.
Unexpected Error: UCS loading process failed.