Is it possible to change the proficiency required for weapons, without changing the weapon base? What I mean is, if I have a weapon with the base weapon as a Sickle, and rename it to a Scimitar, can I change the required proficiency from sickles to scimitars? This is in regards to creating a homebrew weapon, on the site, using the create homebrew tool.

I want to create an improved scimitar,
The base scimitar has 1d6 slashing damage, finesse, and light properties.
The better scimitar will have 1d4 + 2 slashing damage, finesse, and light properties.

In order to do so, I am using the base weapon of the sickle, because its 1d4 slashing damage, and adding in the finesse property. How do I change the required property to wield this new weapon from the sickle, to the scimitar. Or at least, from simple to martial?

Edit: Adding in more details.

If you are the DM then by all means.

If you are a player you should ask your DM

I guess I should have been more clear, in creating a homebrew weapon using the create homebrew tool on the site, is it possible to change the required proficiency without changing the base weapon?

Unfortunately, that is not possible. However, as a quick and dirty solution, you can add a modifier to your sickle named scimitar that gives the character proficiency with it. you can do this by;

add modifier > proficiency -- sickle 

uncheck requires attunement (if desired)

Alternatively, you can edit a character's proficiencies in the characters sheet in the bottom right > PROFICIENCIES & LANGUAGES

hope this helps