Use cloudflare as a proxy for your API

cloudflare-worker.js

async function handleRequest(request) {
	const init = {
		headers: {
		'content-type': 'application/json;charset=UTF-8',
		'Access-Control-Allow-Origin': '*',
		'Access-Control-Allow-Methods': 'GET'
		},
	  }
  
	const  { searchParams } = new URL(request.url)
	let queryParam1 = searchParams.get('queryParam')
	const url = 'https://api.domain.com' + queryParam1
	const response = await fetch(url, init)
	const jsonBody = await response.json()
	JSONresponse = JSON.stringify(jsonBody, null, 2)
	return new Response(api, init)
}
addEventListener('fetch', event =>  {
  	return event.respondWith(handleRequest(event.request))
})