Htaccess rewrite rule

Hi,
I want my server to read this page "https://my-domain.com/myapp.php?p=11" against the URL "https://my-domain.com/myapp/my-technical-effort"
I have tried this htaccess rule
RewriteEngine On
RewriteBase /
RewriteCond %{REQUEST_URI} ^/myapp\.php$
RewriteCond %{QUERY_STRING} ^p=11
RewriteRule ^(.*)$ https://mydomain.com/myapp/my-technical-effort [QSD,R=301,L]

it redirect to new URL but server says page not found on this server with 404 error.
Can you please help me to rewrite the rule so server can serve the page "https://my-domain.com/myapp.php?p=11" against the URL "https://my-domain.com/myapp/my-technical-effort"

My current htaccess is as follows
<IfModule mod_headers.c>
Header always append X-Frame-Options ALLOWALL
</IfModule>
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^(.*)$ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301,NE]
Header always set Content-Security-Policy "upgrade-insecure-requests;"
</IfModule>

Anyone can help me please?