There are ways to spend your cryptocurrency online even on websites that do not accept cryptocurrency.

Gift Cards

If the websites accept electronic gift cards, you could buy a gift card to this online store or service. There are several websites were you can buy gift cards with cryptocurrency and then use these gift cards to make a purchase on the website.

Here are some popular cryptocurrency gift card stores...

Bitrefill - Accounts are optional, Worldwide

Coin Cards - Accounts are optional, Accepts Monero

Cake Pay - Accepts Monero

Pre-paid Credit Cards

If the websites accept pre-paid credit cards, you could buy a pre-paid credit card. There are several websites were you can buy pre-paid credit cards with cryptocurrency and then use this pre-paid credit cards to make a purchase on the website.

Here are some popular cryptocurrency pre-paid credit card services...

spendit - Accepts Monero

Contact The Website And Request Them To Accept Cryptocurrency For Payments

It is worth a shot. Most likely they will just tell you that they will consider it or pass the message along. The more people that take time to do contact these online businesses, the more demand it will create and the more likely a website will start accepting cryptocurrency as a form of payment.