how can I add custom text like "mr." or "mrs." before clientname part in PDF?

Self-Hosted | v4/Legacy
#1

I can’t find which file i should edit.
could you give me some hint?

-self hosted v3.7

#2

In the custom design we display a stack of fields using $clientDetails, you’d need to replace it with the individual fields and you could then use the custom client field for mr/mrs.