INSTRUCTIONS
STEP 1
In Bubble editor, go to Settings -> General - > and activate the option "Expose the option to add an ID attribute to HTML elements."

STEP 2
Place the element 'Open native iOS keyboard' on the page where you want to use the plugin. You can find the element in the section "Visual elements" in Bubble editor

STEP 3
In Bubble editor, click on the button element that you want to use with the plugin.
The bubble inspector window will open.
In the first tab (Appeareance), scroll to the bottom. There is a field called ID Attribute. type in an ID for the button, for example button_id

STEP 4
Do the same as STEP 3 for the input element that you want to use with the plugin.
Set an ID, for example input_id

STEP 5
Click on 'Open native iOS keyboard' element and type in the IDs that you setup for the button element and for  the input element.

DONE :)