You can use TMs to teach Blaze Kick to Blaziken starting on Pokémon GO Community Day on May 19

This month’s Pokémon GO Community Day will take place on Sunday, May 19, 2019, from 3 p.m. to 6 p.m. in your local time zone in various territories across the globe, including the Asia-Pacific region, Europe, the Middle East, Africa, India, the Americas and Greenland. Participants will have the opportunity to catch plenty of Torchic during the three-hour span, and if you evolve Combusken (the evolved form of Torchic) into Blaziken during the event or up to one hour after the event, your Blaziken will learn the special move Blast Burn that it is normally unable to learn. This move will be available only to Blaziken evolved during Community Day. Kicking in on Community Day and going forward, Trainers can use TMs to teach their Blaziken the powerful Fire-type move Blaze Kick. The May 2019 Community Day will also feature triple catch Stardust and three-hour Lures. Shiny Torchic, Shiny Combusken and Shiny Blaziken will also make their Pokémon GO debuts on May 19.

Source: @PokemonGoApp