Main plot:
1918 - Wonder Woman
1984 - Wonder Woman 1984
2013 - Man of Steel
2015 - Batman v Superman
2016 - Suicide Squad
2017 - Justice League / Zack Snyder's Justice League
2017 - Aquaman (several months after Justice League)
2018 - Shazam!
2020 - Birds of Prey
2021 - The Suicide Squad
reference:
https://www.tomsguide.com/how-to/how-to-watch-dc-movies-in-order
Flash of Justice League has a cameo in Arrowverse corssover "Crisis On Infinite Earths". I skipped these episodes from this list, but if you insist:
- Supergirl 5×09
- Batwoman 1×09
- The Flash 6×09
- Arrow 8×08 -> DCEU version of the Flash meets the CW version of the Flash
- Legends Of Tomorrow 5×01