emandem

I've had multiple customers unable to checkout on my website as a error pops up- "Couldn't load page" with a "Try again" button. It doesn't load the checkout page when you press "Try again". It seems to work properly on my phone and my laptop, however my family has tested it and they also receive the error message. I have attached a photo that a customer has sent me below. I'm unsure of how to fix this, does anyone have any advice?