PayPal is not currently a payment option on OpenRouter's checkout. If your card is also being declined, that combination — no PayPal and a failing card — can leave you without an obvious way to pay, but it usually isn't one single problem; it's two separate limitations stacking together.
Card declines in this situation are usually the processor's risk control flagging your card type or region, which a support ticket can sometimes clear, though it may take a few days.
If you want credits now rather than waiting, crypto is a payment method OpenRouter does support, and it works regardless of the PayPal gap. ROZO Checkout accepts BTC Lightning, USDC, USDT and more against an OpenRouter link for a 1% fee, landing in roughly 30–90 seconds. ROZO is independent and not affiliated with OpenRouter or Coinbase.