What you could do is add a Glaive to your inventory and then click on it and customize it. Name it Longsword 1-handed. Add a great axe. Do the same and name it Longsword 2-handed. It will show as two different items (you might be able to make the weight zero or one of them the weight of a longsword if you are paying attention to carry weight). But you can attack with those from your sheet.
Only problem is if there isn’t a weapon of the damage type with the right damage die.
IF you are using a third party extension for the rolls, etc..I would do as ThriKreenWarrior says and use a Glaive as a base. I have published a Homebrew called Superior Longsword for you if you need it. Or, just make it yourself by removing the Glaive properties of Reach, Heavy and Two-Handed and add Versatile and Proficiency Glaive. Aside from being categorized as a Glaive, it should work on the character sheet.
How would I go about changing the dmg die on a weapon like making a longsword that does a d10 one-handed then a d12 when wielded with two hands.
When in doubt.
There's currently no way to do it with the homebrew tools on D&D Beyond.
I have a weird sense of humor.
I also make maps.(That's a link)
What you could do is add a Glaive to your inventory and then click on it and customize it. Name it Longsword 1-handed. Add a great axe. Do the same and name it Longsword 2-handed. It will show as two different items (you might be able to make the weight zero or one of them the weight of a longsword if you are paying attention to carry weight). But you can attack with those from your sheet.
Only problem is if there isn’t a weapon of the damage type with the right damage die.
EZD6 by DM Scotty
https://www.drivethrurpg.com/en/product/397599/EZD6-Core-Rulebook?
IF you are using a third party extension for the rolls, etc..I would do as ThriKreenWarrior says and use a Glaive as a base. I have published a Homebrew called Superior Longsword for you if you need it. Or, just make it yourself by removing the Glaive properties of Reach, Heavy and Two-Handed and add Versatile and Proficiency Glaive. Aside from being categorized as a Glaive, it should work on the character sheet.
Thanks that works perfectly and will be useful for the future.
When in doubt.