Nick here from Shopify.
It can take from 24 up to 48 hrs for your Facebook page to connect. Can I ask if you if it's just connecting the Facebook page to your store or if it's the actual products for the sales channel? But if you have been waiting for 3 days already then I'm thinking something must not be right. I know it sounds obvious, but could you disconnect and try adding it again.
If you try the process again and it doesn't work, can you let me know in a reply here and I can have our higher level support team take a closer look into it for you and see what might be happening.
Hopefully, it works the second time. Looking forward to hearing from you.
All the best, Nick
Can you elaborate a little what you mean and what error you are seeing? If you could screenshot an error message you see or give any more information it would be greatly appreciated. Once I have a better idea of what's happening it will help troubleshoot this for you. Looking forward to hearing from you.