Yes! To invest with an LLC, here's what you have to do:
Use the first and last name fields for the name of the LLC. For example, it may look like [Jane Doe's] [Business LLC], or [Jane Doe] [LLC] so no worries if it looks a bit funny.
Put the EIN in the SSN field.
Use the address associated with the LLC.
Link the bank account associated with the LLC the same way you would any other account.
And you're good to go!