You do not have compare authorization in comparison client (S_TABU_RFC)

You do not have the comparison authorization S_TABU_RFC in the logon
client.
The authorization S_TABU_CLI, required in releases up to 4.5A, has been
replaced by a new authorization S_TABU_RFC. This makes it possible to
assign authorization for maintaining and comparing cross-client tables
separately.

How to fix this error?

Ask your system administrator to assign the comparison authorization
S_TABU_RFC to the RFC user that is to perform the comparison.

Error message extract from SAP system. Copyright SAP SE.