My friend is in Russia, and he wants to send an invitation to invite me to Russia. What if the invitation is sent? What other procedures are there?

I wonder if the invitation he gave you was a business invitation or a personal invitation. But no matter what kind of invitation, you need to go to the local immigration office. You can only go to the embassy or consulate if the immigration bureau sends another invitation letter. If he has given you an invitation letter from the Immigration Bureau, you can go to embassies and consulates in China with the necessary documents. Different types of requirements and documents have different requirements, so I won't repost them here. Requirements for specific documents can be found on the website of the Russian Embassy. You can go and have a look.