If you want to re-send an invitation, follow the steps below:
Step 1: Go to the project for which you want to access the bid.
Step 2: Select the bid room within the tab Manage Bids. There, you will see an overview of all the bidders you have invited.
Step 3: If you click on the three-dotted icon on the top right-hand corner of each listed bidder, "Re-send invitation" should be the first option available.

Step 4: You also have the option to see invited contacts, submit bid for the bidder, or delete them.