Brands often set a minimum requirement for their campaigns to match their targeted reach and the tone of the campaign they want to achieve. For example, a campaign promoting a feminine wash would likely allow only females to join the campaign.
You will see a warning label on the campaign brief, tasks, and steps if you are joining a campaign where you don't meet its minimum requirements, but you can still join the campaign if you wish. Simply take note that there's a high chance for your submission to be rejected.
Some campaigns will apply a hard ban if you do not meet the minimum requirements. This means you will not be able to join the campaign at all. E.g. If you have a clashing campaign