Safe Modules enable additional access-control logic for your Safe. Read more about what they are and how they can be used in this article.
Besides, Spending Limits we currently don't have a designated feature to add Safe Modules. However, advanced users can manually add new modules using a custom contract interaction.
To start adding a new Safe Module to your account, navigate to the "Apps" tab and select the "Transaction Builder" app.
First, you will need to enter the Ethereum address of the mastercopy version that your Safe uses. Here's a list of mastercopy addresses depending on your Safe version.
Safe: Mastercopy 1.0.0
Safe: Mastercopy 1.1.1
Safe: Mastercopy 1.2.0
In the second input field, paste your Safe address. You can find it in the side-menu and use the copy-to-clipboard button to copy the address. After pasting the address, select "enableModule" from the dropdown and paste the Ethereum address of the module that you would like to add in the last input field.
Finally, click "Add Transaction" to stage the module addition and then "Send Transaction" followed by "Confirm" to trigger the transaction that will add your module. From this point just follow the instructions in the app. Depending on your setup, other owners of the Safe might need to confirm the transaction.
After the transaction is confirmed, you will be able to see (and remove) the module that you have added in the advanced settings section.