The dynamic templates block can be used to replace the old dynamic template landing pages and/or create new ones from scratch. Below will outline steps to implement both cases.

Refresh your Dynamic Template Landing Page

On the dynamic template landing page, click 'Edit' to open up the configuration and keep a note of the server path. 

Screenshot 1

Click 'Properties' and convert the page to a folder

Screenshot 2

Click 'Properties' again and convert the folder back to a page

Screenshot 3

On the next screen, select a blank page.

Screenshot 4

Click 'Manage Blocks' and select the new Dynamic Templates block

Screenshot 5

Click 'Edit Content' and under the content tab below input the template server path you saved earlier on. You will need to find it and select it from the list. 

Screenshot 6

Create a Dynamic Landing Page from scratch

Click 'New Page' and add a blank page (see screenshot 4 above)

Click 'Manage Blocks'  and add the Dynamic Templates block  (see screenshot 5 above) 

Click  'Edit Content' choose the template server path from the list (see screenshot 6 above)