Since I don’t have a Russian bank card and Russian phone number，is there a way for foreigners to buy tickets in Petersburg or Moscow？
@crinto The only foreign card that works on some Russian ticket purchasing websites is the UnionPay card (chinese), but it is a card that is not sold in all countries.
The other option is to buy a Tinkoff card upon arrival in Russia. More information: https://russiable.com/how-to-pay-in-russia/
The third option is to buy tickets in cash at the ticket offices. Now there are fewer problems when it comes to purchasing tickets since given the current situation there are not as many tourists as before
I actually have unionpay card，do you have any suggestion about tickets purchasing websites that support unionpay? Many thanks.
Try in Ticketland (only in Russian). Choose option “Bank card”. The website is in Russian but you can use your browser’s automatic translator. If the card does not work, contact the bank that issued your UnionPay card because they often block Internet operations carried out in distant countries.