If you can't sign in to your wallet
Check the browser's mode
If you opened a tab with private browsing enabled, you most likely won't be able to sign in to your wallet. Autofill and saving of changes in cookie files don't work in this mode.
Switch to another Safari window (with private browsing disabled) and select "File" → "New window". After that, try signing in to the wallet once again.
Check the cookie settings: for desktop
If, during the payment process, the browser asks to use cookie files from yoomoney.ru, click "Allow".
If the browser doesn't ask for anything, and you can't sign in to the wallet:
1. Sign in to the Privacy section of browser settings.
2. Make sure the "Prevent cross-site tracking" box is not ticked.
3. Make sure the cookie file blocking is disabled.
After that, return to the purchase and try to sign in to the wallet once again.
Check the cookie settings: for mobile
You can manage cookies in the general smartphone settings.
1. Find your browser in the settings
2. Make sure the cross-site tracking is not forbidden + cookie file blocking is disabled.
3. Return to the purchase and try to sign in to the wallet once again.