How do I configure my api node to receive ISO-8859-1

Question

Today I have a Node.js server that has an API service for customers. An example would be receiving a CRM webhook.

router.route('/webhook/service/notifications/crm/syonet/convert')
.post(convertSyonet)

module.exports = router

Where a CRM sends the following header in the request:

Content-Type: application/json;charset=ISO-8859-1

And with that my server returns the following error:

<h1>unsupported charset &quot;ISO-8859-1&quot;</h1>
<h2>415</h2>
<pre>UnsupportedMediaTypeError: unsupported charset &quot;ISO-8859-1&quot;
    at jsonParser

How do I accept the request for this crm?