Both those functions are part of Image Processing Toolbox. Check the output of the ver function to determine if you have this toolbox installed. If you do have it installed, use license to determine if a license for this toolbox is available. [Your company or educational institution may have licenses but they may all be in use when you're trying to use it.]
The notes at the end of their documentation pages indicate they were each introduced in release R2020a, so even if you had Image Processing Toolbox installed and have an available license in your older release those functions would not be available.