Cannot load WP admin after auto-update

My site auto-updated to WP v 6.0.2 and I have not been able to log into the WP admin page – it instead shows a number of events-manager related errors.

I have tried to revert back to earlier WP versions but same errors exist. Examples below but there are lots more. I have not updated the plug in recently but cannot do through WP front end as this won’t load. Can it be done by copying the files or are there also DB updates involved?

Any help appreciated (site is wbagolf.co.uk)

Deprecated: Return type of EM_Tickets_Bookings::key() should either be compatible with Iterator::key(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/cq9rlo83oqli/additional_domains/wbagolf.co.uk/public_html/wp-content/plugins/events-manager/classes/em-tickets-bookings.php on line 308

Deprecated: Return type of EM_Tickets_Bookings::valid() should either be compatible with Iterator::valid(): bool, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/cq9rlo83oqli/additional_domains/wbagolf.co.uk/public_html/wp-content/plugins/events-manager/classes/em-tickets-bookings.php on line 319

Deprecated: Return type of EM_Tickets_Bookings::rewind() should either be compatible with Iterator::rewind(): void, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/cq9rlo83oqli/additional_domains/wbagolf.co.uk/public_html/wp-content/plugins/events-manager/classes/em-tickets-bookings.php on line 294

Deprecated: Return type of EM_Tickets_Bookings::count() should either be compatible with Countable::count(): int, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/cq9rlo83oqli/additional_domains/wbagolf.co.uk/public_html/wp-content/plugins/events-manager/classes/em-tickets-bookings.php on line 325

Deprecated: Return type of EM_Tickets::current() should either be compatible with Iterator::current(): mixed, or the #[\ReturnTypeWillChange] attribute should be used to temporarily suppress the notice in /home/cq9rlo83oqli/additional_domains/wbagolf.co.uk/public_html/wp-content/plugins/events-manager/classes/em-tickets.php on line 266