Customer cus_**** does not have a linked source with ID tok_****

In short : remove the source parameter from the Charge::create([]) if you have
already included it inside the Customer::create([])

In Brief :

There are three different ways to create a charge:

with the source parameter only. In this case, source needs to be a token or 
source ID (created by Checkout or Stripe.js), i.e. a string that starts with 
tok_ or src_.

with the customer parameter only. In this case, customer needs to be a customer 
ID, i.e. a string that starts with cus_. The customer's default payment source 
will be charged.

with both the customer and source parameters. In this case, customer needs to 
be a customer ID as in the previous case, but source should be the ID of a 
payment source that is already attached to the customer. Payment sources can be 
cards (ID starts with card_), bank accounts (ID starts with ba_) or sources 
(ID starts with src_).

In your case, you're passing a token ID in the source parameter along with a 
customer ID in the customer parameter.

If this is a new card, you should first use the token to create a card on the 
customer, then create the charge with the card ID. If the card was already 
saved for this customer, then you don't need to collect the card information 
again (and thus don't need to create a token at all).