When we’re looking for the command we need within dbatools to fulfil our needs I cannot recommend
Find-DbaCommandhighly enough. This command will search all other commands for the pattern you pass in. Today we know we want to find references in stored procedures so let’s see if there is a command that will help.
Seems like querying
sys.sql_modules is a little easier, though if this is a step in a pipeline (such as finding old procedures based on some no-longer-appropriate code snippet and deploying new versions), this can be a good first step.