Here are the steps on how to bulk select due tasks and start working on them in the Chrome extension.
Step 1
Click on the tasks icon on the Chrome extension.
The number next to the icon signifies the number of all pending tasks.
Step 2
Click the "select all" button to check all tasks or selected the tickboxes next to the tasks to select a group of tasks
Step 3
Scroll down and click the "start tasks" button.
Step 4
Do the task ( i.e. Call back ) and click the "mark as complete" button when done.