Hello,
Please make sure that you have created a page and add the code to the page as mentioned
in the screenshot.
[woocommerce_my_account]
Screenshot for Clarification: https://ibb.co/SvQJV07
Then Go to WooCommerce >> Settings >> Advanced.
Set My account page from there.
Screenshot for Clarification: https://ibb.co/1G5D5RC
Then check back. If the issue still occurs then provide the admin panel login details of the website.
Best Regards