No handler found for adding new email sender

Elastic search version 7.9.1
Kibana version 7.9.1

alerting plugin ( opendistro-for-elasticsearch/ alerting-kibana-plugin ) :- Downloaded the plugin folder from
and placed the folder in kibana/plugins folder

I tried to add Email as a destination. I have the errors below
manage sender -> add sender

‘{“error”:“no handler found for uri [/_opendistro/_alerting/destinations/email_accounts/_search] and method [POST]”}’,

After the add a new sender using the below screen immediately says no handler found