What’s the difference between by submission and by invitation?

In “By Submission” campaigns, KOL can both sign up to campaign or be invited by advertiser to a campaign. But, KOL do not need advertiser’s approval to enter the campaign. KOL can directly submit content draft by clicking “more details” button on the campaign and click “submit draft”. Advertisers will later review the draft and if approved, KOL will be paid after uploading the posting link.
In “By Invitation” campaign, KOL can both sign up or be invited by brand. If KOL sign up, KOL need to wait for advertisers’ approval first to be eligible to enter the campaign. After approved by the advertiser, KOL can submit draft and will be paid after uploading posting link.