Is it a red flag to guys if a woman has no friends?

I had plenty of friends back in my small town back in Texas. I had been living in San Francisco for 4 years for work and haven’t been able to make a single friend here because the only ways to make friends in this city are through shared hobbies (yoga, pilates, biking, etc) or social events like concerts or meetup groups. I’m not interested in that stuff because I’m super shy, quiet and socially awkward. It’s so hard to make friends here unless you’re a social, outgoing person. I’m too scared to go on dating apps because I don’t want the local guys to think I’m a red flag or a friendless loser.