Content security policy header list using web config file

Question

I am Facing following Content Security Policy issue in my existing mvc project.

We used https://sitecheck.sucuri.net/ to check security scan

Issue -

Security Headers

Missing security header for XSS Protection. Affected pages:

Missing security header to prevent Content Type sniffing. Affected pages:

Missing Strict-Transport-Security security header. Affected pages:

Default server banners displayed. Your site is displaying your web server default banners. Affected pages:

https://www.example.com/404javascript.js

https://www.example.com/404testpage4525d2fdc

We are trying to resolve that using web config file with following configuration:

`<customHeaders>

<remove name="X-Powered-By" />

<add name="X-Frame-Options" value="DENY" />

<add name="X-Xss-Protection" value="1; mode=block" />

<add name="X-Content-Type-Options" value="nosniff" />

<add name="Referrer-Policy" value="no-referrer" />

<add name="X-Permitted-Cross-Domain-Policies" value="none" />

<add name="Strict-Transport-Security" value="max-age=31536000; includeSubDomains" />

<add name="Feature-Policy" value="accelerometer 'none'; camera 'none'; geolocation 'none'; gyroscope 'none'; magnetometer 'none'; microphone 'none'; payment 'none'; usb 'none'" />

</customHeaders>

<httpRuntime targetFramework="4.6.1" maxRequestLength="1048576" requestValidationMode="4.0" executionTimeout="110" enableVersionHeader="false" />`

But we are still facing same issue after changing configuration, please look at our process where we are wrong or any alternate solution.