Hello, thanks for wanting to support the site in this way. There's currently 2 option for doing so:
Why donate? While the site is free to use it's definitely not cheap to run. Without going much into detail, donations are needed to expand the number of servers and bandwidth necessary for you to download more games at a decent speed.
Note: Paypal donations can be either a one time or recurring (monthly) donation, cancel is possible at any time. You can insert any amount you want (minimum is $1). No Paypal account is required only a valid credit/debit card unless it's recurring.