Make comments edit and cancel edit button usable with keyboard only

Related to WCAG 2.1.2 criteria (level A): no keyboard trap.
https://www.w3.org/TR/WCAG21/#no-keyboard-trap

related to WCAG 2.1 level A criteria 2.1.1: Keyboard
https://www.w3.org/TR/WCAG21/#keyboard

Location of the element: "Comments" tab section, under the "Tags" heading, in the main content.

Steps to reproduce
1. Enter any comment in the "Write a comment here" edit field.
2. Then click on the "Save" button. Then the comment will add in the comments tab section.

USING THE KEYBOARD ONLY FROM NOW ON
3. Access the "More options" button from the comment using the tab key.
4. Press enter to open the menu
5. Use the arrow keys to access the edit option
6. Change the comment, DO NOT CONFIRM OR CANCEL
6. Try to confirm or cancel using the keyboard only

=> Comment can be submitted by pressing Ctrl+enter, however using the tab key does not provide a way to access the confirm button
=> Cancel button does not have a keyboard shortcut and using the tab key does not provide a way to access it
Expected: Both buttons should be accessible with keyboard only by using the tab key, and using the enter key should allow a user to action them

Recommendation to fix
RULE :
Functionality MUST be available using the keyboard, unless the functionality cannot be accomplished in any known way using a keyboard.

HOW TO FIX:
Fix this issue by ensuring the component can be used by the keyboard OR by providing a conformant alternate functionality method for the action

REFERENCE:
Deque University:https://dequeuniversity.com/class/input-methods2/keyboard-input/functionality

BACKGROUND:
Some people cannot use a mouse due to vision or motor disabilities. Content that can be operated with a mouse must also be made operable with a keyboard. When content is operable through a keyboard, it becomes operable by a variety of assistive technologies such as speech input software, sip-and-puff software, on-screen keyboards, scanning software, and alternate keyboards.