At the point that you provide services as a Main RSP for a delegated gTLD, you need to be onboard with the TMDB (https://marksdb.org).
In the case of the RSP program, RST v2.0 will be used to verify that the RSP applicant's platform is capable of supporting the Rights Protection Mechanisms. You don't need to connect to the TMDB for purposes of the RSP program as testing material will be used. The testing material can be found here: https://newgtlds.icann.org/sites/default/files/new-smd-test-repository-22nov22-en.pdf
The definition of the structure of the testing material can be found in Section 6 of RFC9361, and the definition of an Signed Mark Data (SMD) file may be found in RFC7848.
More information about the RPM test cases may be found here: https://icann.github.io/rst-test-specs/rst-test-specs.html#Test-Suite-MinimumRPMs