I grabbed this item from The DM Lair and want to add it to my campaign in D&D Behond.

Here’s the item description.

Boots of Thumping
Boots, rare (requires attunement)

While wearing these boots, if you take the Attack action on your turn, you can use a bonus action to make an unarmed (kick) attack that deals 1d6+ STR mod damage. On a critical hit, your kick hits your target just right, deals quadruple damage (instead of double), and stuns the target until the end of its next turn. You also have advantage on Strength (Athletics) checks when using your boot to kick down doors.

Here are my questions:

1. Should I make this armor or a wondrous item or something else?
2. What modifier type do I add to make this show up as a bonus action that does 1d6+STR damage?
3. Is there any way to add the CRIT damage modifier?
4. I think I figured out how to give advantage on athletics checks but if anyone has some input, I’ll take it.

Is there anything else I should know about creating this item?

TIA.

1. I would make it as a handaxe since it naturally deals 1d6 + Str on a hit. There is no other way to get it to have a rollable attack and damage rolls other than starting with a weapon that does the exact amount of damage you want. You would then have to add Modifiers to change the damage type and remove the thrown property. You could also add a Modifier to grant proficiency with that weapon if necessary.
2. No, but if you use a weapon like a handaxe, it can be customized directly on the player’s character sheet as “dual wield” and it will then move to the bonus action section of the Actions tab for that character.
3. Nope, that’ll have to be done manually by the player.
4. Modifier: Advantage->Subtype: Athletics->Description/Details: “when kicking doors”

Thank you so much for your input. I’ll try this out.