The Task Log on the Environments page lists all tasks performed on each of your environments during the last seven days. This task log shows the last 50 tasks or the tasks for last 7 days, whichever is less.
If you want to see the tasks older than last 50, you can use acli command to get the list of tasks using this command -
acli api:applications:notification-list <applicationUuid>
It is going to give you a detailed information of the tasks. You can use various parameters to filter this data, as described here -
acli help api:applications:notification-list Description: Returns a list of notifications associated with this application by its UUID. Usage: api:applications:notification-list [options] [--] api:applications:notification-list da1c0a8e-ff69-45db-88fc-acd6d2affbb7 --sort="field1,-field2" --limit="10" --offset="10" api:applications:notification-list myapp --sort="field1,-field2" --limit="10" --offset="10" Arguments: applicationUuid The entity's universally unique identifier. You may also use an application alias or omit the argument if you run the command in a linked directory. Options: --sort=SORT A comma-delimited string with fields used for sorting. The order of the fields is significant. A leading - in the field indicates the field should be sorted in a descending order. Not all fields are sortable. --filter=FILTER The filters query string parameter restricts the data returned from your request. Filtered queries restrict the rows that do (or do not) get included in the result by testing each row in the result against the filters. Not all fields are filterable. --limit=LIMIT The maximum number of items to return. --offset=OFFSET An integer to signify the offset to paginate from.