Unfortunately, you cannot directly disable HSTS on your website once it's been enabled. Here's why and what you can do:

Why HSTS Cannot Be Disabled

Browser-Side Enforcement: HSTS is a security feature that instructs browsers to always connect to your site over HTTPS (secure connection). Browsers store this setting, making it impossible to override from the server side once set.
Security Mechanism: This persistence is intentional, protecting users from man-in-the-middle attacks that could downgrade connections and expose sensitive data.
What You Can Do

Wait for HSTS Max-Age to Expire:

When you enabled HSTS, you included a max-age directive, which specifies how long browsers should enforce it (usually in seconds).
After this period expires, browsers will forget the setting, allowing you to access the site over HTTP if needed.
To find the max-age:
Web Server Configuration: Check your web server settings for where the HSTS header might be set.
Developer Tools: Open your browser's developer tools (usually F12), go to the Network tab, and inspect the HTTP response headers from your website. Look for the Strict-Transport-Security header.
Clear Browser HSTS Settings (For Development/Testing):

This should only be done for development purposes and with caution, as it reduces your site's security for anyone using the affected browser.
Chrome:
Type chrome://net-internals/#hsts in the address bar
Under "Delete domain security policies", enter your domain name and click "Delete."
Firefox:
Go to your browsing history (Ctrl+Shift+H or Cmd+Shift+H on Mac)
Find your website, right-click, and choose "Forget About This Site." It will clear all site data, including HSTS settings.
Remove the HSTS Header (Future Prevention):

Locate the code or configuration area on your server where the HSTS header is added and remove it. This won't solve your immediate problem but will prevent it from reoccurring.
Important Considerations:

Don't disable HSTS permanently: HSTS is vital for website security. Only remove or bypass it temporarily for essential debugging. Re-enable it as soon as possible.
Correct the underlying issue: Find out why you need to connect to your site without HTTPS and address that instead of removing HSTS. Sometimes issues like mixed content (HTTP elements on an HTTPS page) might be the cause.
Let me know if you have further questions or need clarification on any steps!