This is from https://www.irs.gov/retirement-plans/how-much-salary-can-you-defer-if-youre-eligible-for-more-than-o...

Deferrals limited by compensation
Although plans may set lower deferral limits, the most you can contribute to a plan under tax law rules is the lesser of:

the allowed amount for that plan type for the year, or
100% of your eligible compensation defined by plan terms (includible compensation for 403(b) and 457(b) plans).