You can either pay your RPRF upfront at the time of the application or at any other time.
If you are in Canada and IRCC sends you a PPR with instructions to send your passport to a specific country for visa processing, then I believe you should request to change the location of the embassy/consulate or visa application center (VAC) to where it is convenient for you to submit your passport, and it is my understanding that IRCC will then issue you a new PPR with updated instructions. You should never mail or send your passport to a foreign country.
If you are in Canada and IRCC sends you a PPR with instructions to send your passport to a specific country for visa processing, then I believe you should request to change the location of the embassy/consulate or visa application center (VAC) to where it is convenient for you to submit your passport, and it is my understanding that IRCC will then issue you a new PPR with updated instructions. You should never mail or send your passport to a foreign country.
I have a couple of questions, if someone could answer.
Can I pay the RPRF now (a few days after mep) or only when it's approved?
I am applying to observerships in Canada and I might be called for one before the PPR arrives. Is it ok to be in Canada (as a visitor) when I get my PPR?
Thank you