Here are the remaining MER events for eventing. It's changing daily, with cancellations / postponements coming left and right...
https://inside.fei.org/system/files/OG Eventing 2021 Calendar 26March2021.pdf
Notably, although the dealine is June 20th, Millstreet CCI4*-L will end June 6th, and it will represent the final chance for most who are still seeking their qualification...