Tipping Etiquette (Tunisia)

My family and I are visiting Tunisia next month. The hotel is Nour Palace Resort in Mahdia.

We booked an All Inclusive package deal through On The Beach. The reviews for the hotel seem to be positive, however a lot of the reviews emphasize this hotel is very insistent on tips, with some reviewers stating you will be ignored if you don't.

I must admit it is a bit frustrating as the reason we wanted an All Inclusive holiday was to eliminate the stress of worrying about money, however I have no issues with tipping if that's the cultural norm. The thing I worry about is how much I should be tipping, how frequently and to who? Also what is the preferred tipping currency in Tunisia?

Do I tip waiting staff at the buffets? If so, do I do it every time we eat? Do I tip the bar staff every time we get a drink? The housekeeping? Lifeguards?

Would really appreciate some advice on this as I've never been to a resort that requires tipping.