You cannot add your Chek card to your PayPal wallet. The league must send you an invoice with a payment link. Use that link to pay with your Chek card.
Do not send money to a personal PayPal account. If you do, the payment will be declined. This could also disqualify you from the Every Kid Sports Pass and other programs.
Is your league having trouble accepting payments through PayPal? They need to contact PayPal support directly. Every Kid Sports and Chek cannot make changes to PayPal accounts.