createCheckout giving 400 bad request

[amosbastian]

I am trying to create a checkout, but can't pass the store or variant as per the documentation

Argument of type '{ store: string; }' is not assignable to parameter of type 'CreateCheckoutOptions'.
  Object literal may only specify known properties, and 'store' does not exist in type 'CreateCheckoutOptions'.

I am using this version:

"lemonsqueezy.ts": "^0.1.6",

If I force the type as any and call it with the store and variant, then it results in a 400 error