then they ask :" You also need to provide a photo of a document confirming your location along with your document, like a receipt from a coffee shop"
this is the first time ever bookmaker ask me to go to my street and buy something keep the receipt and take selfie with
Are you sure what the casino representative meant was a receipt from a coffee shop? Or what he meant was a utility bill receipt to prove that you actually reside in the geographical location you filled while verifying your account details?. Because asking for Utility bill is a common criterias which are always been needed for account verifications, as it involves recurring charges for home maintenance such as Electricity bill, Water bill, Gas bill, Internet bill, Phone bill, Cable TV Subscription bill and Waste Management Bill. And as such, any of these documents can be used in verifying your account as utility bill, inasmuch as it's still not more than 2 or 3 months old. As some casinos can specify that the utility bill should not be more than 2 months old.
Believe me reading the OP statement about going to the shop to get snacks and snapping the receipt for KYC requirements from the casino was a little funny and off if actually that really happened. And just like him I have seen not come across something that when it comes to KYC verification from any casino and I know I have gambler and verify a couple of my casino account both online and offline the community and not once seen this although it can be as you have said it, maybe what the casino meant was a different thing to what the Op is saying or due to lack of good understanding.