Where does ps-printer-app look for cupsFilters?

[kvsrikantha]

On Ubuntu 24.04, Got ps-printer-app Version 20240504-9 as snap.

1. Successfully added PPD for Konica Minolta 754e.
2. Tried adding PPD for Konica Minolta 958:
   The PPD has a line *cupsFilter: "application/vnd.cups-postscript 0 KMbeuEmpPS.pl"
   I put the KMbeuEmpPS.pl file at:
   /var/snap/ps-printer-app/current/usr/lib/ps-printer-app/filter/KMbeuEmpPS.pl
3. I got error:
   FAIL Missing cupsFilter file "/snap/ps-printer-app/1362/usr/lib/ps-printer-app/filter/KMbeuEmpPS.pl".
4. I tried adding the KMbeuEmpPS.pl at above place ...got read only file system error.
5. What should I do?
6. Another error:
   FAIL Multiple occurrences of option KMAuthentication choice name Server.
   ..even though this is the ``official'' PPD from manufacturer.
   What should I do?

Any help would be much appreciated.

PPD:

Konica-958.txt