"save as" not working in Firefox and Safari

**Current Behavior:**
The "save as" button doesn't open the save file dialog and throws the following error in the console:
`Uncaught (in promise) TypeError: window.showSaveFilePicker is not a function`

**Expected Behavior:**
It should open the save file dialog.

**Steps to Reproduce:**
Use Firefox or Safari and click on "save as".

**System Information:**
Firefox / Safari
MacOS