This is a great side gig that can also lead to a career if you want to learn the programs and go down that road. I have only explored this a little but have made decent money. You never know what a project will bring, one could be teaching a self driving vehicle to to avoid objects or watching plants grow.

SparkIA: Check their career page often for freelance opportunities or just send them an email and ask if they have any openings.

Telus: This company does so many thing and Image/Data Annotation is one. you will have to check often for these gigs.

Humans In The Loop: Check out the Annotation Services page to see what image annotation looks like. not hard and anyone can be trained to do the basic stuff. They do not say anything about needing experience so apply even if you have none and want to get started.

Cayuse Commercial Services: They currently have a Data Labeler job open that says nothing about previous experience needed.

Gigs on PeoplePerHour:

Gigs on HireArt: This is a current listing on HireArt: Data Annotation Manager