CORS issue with using fetch ,No 'Access-Control-Allow-Origin' header is present on the requested resource

Question

I'm trying to access a balldontlie API endpoint to be able to add a search bar to my web project through a template I found online, but I'm running into a CORS error while implementing this. The exact statement says ":5500/hoops.html?search=Lebron#:1 Access to fetch at 'https://www.balldontlie.io/api/v1/players?search=Lebron' from origin 'http://127.0.0.1:5500' has been blocked by CORS policy: No 'Access-Control-Allow-Origin' header is present on the requested resource. If an opaque response serves your needs, set the request's mode to 'no-cors' to fetch the resource with CORS disabled."

This is what the code loos like:

const options = {
    mode: 'cors',
    'Authorization': "myAPIKey", // i have my own, just hiding it for the post//
     method: 'get',
    
    }
function searchPlayer() {
 //retrieve info from input
 const playerNameInput = document.querySelector("#playerInput");

 //trims name whitespace
 const playerName = playerNameInput.value.trim();

 //if player name is blank, alert is shown and ends functionality
 if (playerName === "") {
     alert("Please enter a player name");
     return;
}
const apiUrl = "https://www.balldontlie.io/api/v1/players?search=" + playerName;

//fetch data from the api (plus the appended player)
fetch(apiUrl, options)
    //converts api response to json format
    .then(response => response.json())

    //executes after data is fetched
    .then(data => {

        //if there is a player in the array =
        if (data.data.length > 0) {

            //player variable contains data from the first player found in the api response
            const player = data.data[0];

            //calls function to display player info 
            printPlayerInfo(player);

Ive went to other posts with this issue but im still finding difficulties. Someone suggested to add these lines to the back-end.

Access-Control-Allow-Origin: 'http://127.0.0.1:5500';
Access-Control-Allow-Credentials: true;
Access-Control-Allow-Methods: GET, POST, OPTIONS;
Access-Control-Allow-Headers: Origin, Content-Type, Accept;

I don't know what that does or how it would help. Any Advice is appreciated, thank you.

I tried to go around copying and pasting solutions that didn't include going through a third party but I dint find what I was looking for. I'm fairly new to javascript and I'm learning as I go with this project using html, css, and barebones javascript. I dont want to go into angular or react yet.