As long as your submissions are still PENDING, the options to edit, re-submit, and withdraw them will be available.
On the bottom menu of the TRIBE app, tap POSTS, and go to PENDING under the campaign type of the submission.
Tap the MORE OPTIONS icon (...) on the top right of the pending submission card that you want to manage.
Select Edit & Re-Submit to update info (the caption can be updated as well for Influencer Campaign submissions). Tap Submit to finish.
Select Withdraw Submission to withdraw your submission from the campaign. If you withdraw your post, it cannot be resubmitted.