If you need to prove you are currently not on probation, yes, of course, documentation clearly indicating this would be needed and that would necessarily be copies of official court records.
Is that what you need to do in responding to the letter from IRCC? That depends on what the letter requests.
What YOU need to SUBMIT to IRCC should be relatively clear in the communication you received. An explanation? Particular documents?
If IRCC specifically requested documentation as to your current status, as to being on probation or not, it is undoubtedly requesting documentation from the respective court as to your status in that court.
Meanwhile the issue of prohibitions is broader and more complicated than when a period of probation applies or is terminated. I do not know what is stated or asked in the letter you received, but my guess is that at the least IRCC wants some detailed information about the case which involved you being on probation, even if that has ended.
Generally, individuals applying for citizenship who have current, pending, or recent criminal cases, should consult with a lawyer who actually reviews the individual's specific situation . . .
. . . or otherwise have confidence in their understanding of the prohibitions and how to report and respond accordingly.