I made a bunch of homebrew magic items for my party and they are all part of my campaign but they cant search for my items. I've enabled content sharing.

They won’t be able to search for them outside of the campaign.

In the character builder, on the Home tab, the toggle next to “Homebrew Content” needs to be on (red, to the right) for those PC for their players to be able to add those items to their character sheets.

If you just want the items to be visible for them to read them you have to copy the URLs for those items and either send them to your players in a group PM, or post those links in the public campaign notes for your players to be able to click them.

Quote from IamSposta >>

They won’t be able to search for them outside of the campaign.

In the character builder, on the Home tab, the toggle next to “Homebrew Content” needs to be on (red, to the right) for those PC for their players to be able to add those items to their character sheets.

If you just want the items to be visible for them to read them you have to copy the URLs for those items and either send them to your players in a group PM, or post those links in the public campaign notes for your players to be able to click them.

 How do I copy the URL properly? When I try to do so, they keep getting 403 error messages.

They have to be in the same DDB campaign with you to see it, and they have to be logged in too.