In most regions, you can contact your local SRAM dealer and request a SRAM 12-speed alignment tool for eTap AXS front derailleurs free of charge. If the dealer does not have one in stock, you can use its part number, 00.7618.170.000, to facilitate your search.
Below are video resources on the installation of a front derailleur with the tool:
For instructions on how to install an eTap AXS front derailleur without the alignment tool, check out the user manual: Front derailleur installation without a set up tool.
For RED AXS front derailleurs, a different set up tool is required: How do I set up the RED AXS front derailleur?.