CORS issue when trying the Simple Dapp

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(09:24:43 PM) MTIBAA Riadh: Please how to solve this problem
(09:24:46 PM) MTIBAA Riadh: Cross-Origin Request Blocked: The Same Origin Policy disallows reading the remote resource at (Reason: CORS request did not succeed). Status code: (null)
(09:25:47 PM) MTIBAA Riadh: I have got these errors when implementing your Build a Simple dApp in 3 Mins - Cloud Function
(09:25:52 PM) MTIBAA Riadh: thank you

it looks like that server 9c8nrl6lfq8u doesn’t exist, where from is that server url?

Thank you for the reply

that server it is in the script example

const serverUrl = ""; Of course I use a server defined in the platform

I mean, that server is your server, in your account? it is working fine? can you see it in admin interface?