The 2005 Toyota Tacoma's automatic transmission fluid (ATF) fill location isn't a simple dipstick like engine oil. Instead, it's filled and checked through a specific port on the transmission itself, usually requiring a specialized tool or a very precise method.
You should not attempt to add ATF directly without consulting your owner's manual or a qualified mechanic.
Improperly adding or checking the ATF can damage the transmission. The owner's manual will have the specific instructions, and a mechanic will have the proper tools and knowledge to do it correctly. Trying to find the fill point yourself without the proper information is strongly discouraged.