The whole process explained in this article see in video at the end of the article
Once both rate plans are created, next step is to map those two rate plans so they can be synced. Here is how you can do it:
First in the upper right corner click on the name of your property choose Property settings and go to Channel manager tab. After that select the small pen icon on the active Booking.com connection:
On the next screen you can find your existing units and rate plan mappings. On the left side you'll see your Rentlio rate plans and on the right side Booking's rate plans.
You can create as many rate plans as you want on Rentlio and Booking.com. By clicking on the Remap rates button you'll be able to pair two new rate plans. In our example we are doing the pairing or the mapping of the Non refundable rate plan (you can apply this process to any rate you have).
After you clicked on Remap rates button, now from the right dropdown menu select the Booking.com newly created rate plan.
Now choose green button Save mapping to save all changes. You may continue to use Rentlio by going to your calendar and go to your extranet calendar on Booking.com to see is synced properly.
The whole process described above you can see in this video below.
Pro tip: right click on video and then select open in new tab to see larger preview.