Annual tax statement using FIFO

A novice investor here looking for help with tax statements. Does anyone know a simple way how to track capital gains and losses using the FIFO principle? I tried to make an excel sheet but I’m not the most tech-savy type so it didn’t end up working. My country’s tax officials require the use of the FIFO principle. I’ve already made some sales so I have to figure out a way to do it. Any help would be much appreciated!