There's many variations of Cable Curls - here: two-arm standing Cable Curls are shown. Other options include lying, one-arm, across body (i.e. to opposing shoulder), on a preacher bench.
Your shoulder muscles play a massive role as a stabilizer during this exercise. Remember this, stable! There should be relatively little movement around your shoulder joint, if there is, lesson the weight!
Exercise image from Gym Professor Shuffle free gym workout app.