The Maximum Number of Terms property allows you to specify a limit of maximum terms a user can add to an entry. Once you set this limit, users will be restricted from adding terms beyond the specified maximum.
Note: The maximum number of terms allowed per entry is 25.
To set the maximum number of terms for a taxonomy, log in to your Contentstack account and go to the stack. Perform the following steps in the stack:
Note: By default, the UID for the taxonomy field is set to taxonomies and cannot be updated.

Additional Resource: Refer to our Add Taxonomy to a Content Type document for more information.