Inline Create for Google Sheets

Setting up inline create in Google Sheets

Go to the fields on the table that you want to enable the inline create on.

Click on the cog next to that field, this will bring up the configure screen. Choose link to another record and pick table and field you would like to link to.

Then go to edit the layout and choose to edit the field you have just linked, an option to "Show add new button" should now be available.