Asked to tip before sitting down

I went to this restaurant in Long Beach, CA. I don’t want to say names. It’s about Cajun food. It’s easy to search. I was asked to tip before sitting down because we order before sitting down. The restaurant is a sit down restaurant but they just let you order at the door. Ok fine, after paying it and sitting down there is a sign says “no table service”. You can’t make this stuff up. When you don’t have service, you shouldn’t have the tipping option and mislead people into tipping!