Typically, for a first purchase of in-game currency, it would be 24-48 hour wait. Also, you have to log-in with your Epic account to claim purchases on your Epic Account. You can't just try something like buying it on Epic and trying to claim it on Seam or MS Store version of the game. If you buy on Epic, you have to claim while logged in on Epic. Contrary to what some people seem to think, the link is only to share characters and progress on other platforms. Purchases and the like are still tied exclusively to the platform it was bought it and can only be used on other platforms after being claimed on the account that bought it. It would be so much easier if we just had an account through Sega and made purchases through Sega, though. Then, we would always get in-game currency purchases right away.