Going by your package name, I'm assuming you're running Red Hat or CentOS. Running both 8.1 and 9.2 at the same time on that OS could be a bit tricky and this isn't really the proper medium for discussing how to do so.
What you could do is copy the 9.2 pg_dumpall binary from the machine you have it installed on now and put it on the other machine. As long as they're the same OS/architecture that should work fine. The other option is to open up a network connection between the two systems and allow pg_dumpall from the 9.2 system to connect to 8.1 on the old system.