Please refer the below steps to tag a vendor for any asset:
Step 1 : Go to Admin >> Assets & Inventory Tracker >> View All
Step 2: Click on Assets tab >> Click on Active Assets Sub tab >> For the listed Assets, click on “More Details” a separate window pops up.
Step 3: Click on Contacts tab , and you can see all the Maintenance contacts listed. Select the corresponding vendor and click “Assign Contact”
Note : Please add the vendor details in Maintenance contacts application before tagging.