Verify a Superpermutation A superpermutation on n symbols is a string which contains every permutation of n symbols in its body. For instance, 123121321 is a superpermutation on three symbols because it contains 123, 132, 213, 231, 312 and 321 as substrings.
The Challenge
Given a string composed of n unique symbols (and, optionally, n), output whether it is a superpermutation on n symbols.
Rules

This is code-golf so the shortest answer in bytes wins.

Assume only valid input will be given.

Assume n is greater than 0

Input and output can assume whatever form is most convenient, e.g. the series of symbols can be a string, a list, an integer, a set of n bitmasks, etc, so long as it is indicated in the answer. Additionally, anything may be used as a symbol provided it is distinct from all the other symbols.


Test Cases
In: 1234
Out: False

In: 1
Out: True

In: 11
Out: True

In: 123121321
Out: True

In: 12312131
Out: False

See also: this question about generating superpermutations
05AB1E, 4 bytes
ÙœåP

Only takes input \$J\$ (I don't need \$n\$ with this approach).
Try it online or verify all test cases.
Explanation:

Ù     # Uniquify the digits of (implicit) input-integer
 œ    # Get all permutations of this uniquified integer
  å   # Check for each if it's a substring of the (implicit) input-integer
   P  # And check if this is truthy for all of them
      # (after which the result is output implicitly)