将example.com重定向到example.com/blog

I have uploaded my website under a sub-directory on my server the structure is looks something like this

root

----blog

--------.htaccess

----apple

----.htaccess

Now I have written a rule inside my /blog/.htaccess file which will redirect users to

https://www.example.com/blog/

I have done this by adding the following rule.

RewriteEngine On
RewriteBase /blog/

RewriteCond %{HTTP_HOST} !^www\. [NC,OR]
RewriteCond %{HTTPS} !on
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://www.%1%{REQUEST_URI} [R=301,L,NE]

so far so good it is working exactly like the requirements, Now the real issue come. User wants that when ever any one hit the domain without the preceding blog it will add the /blog/ and redirects the user to the blog site and this rule should not effect any sub-domain means if

User enters the url.

example.com

He should be redirected to.

https://www.example.com/blog/

And when he enters url.

apple.example.com

He should redirected to

apple.example.com

Now In order to do so I am writing the following rule but it is not working the rule looks like this.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^example\.com$
RewriteRule (.*) https://example.com/$1 [R=301,L]
RewriteRule ^$ /blog/ [L]

I don't know what I am doing wrong.

I have added so much detail because I thought may be the .htaccess file inside the blog directory is making an issue.

Found the issue with the help of @Twinkle the real issue was that I was adding

RewriteRule ^$ /blog/ [L]

which I didn't needed for obvious reasons by removing this rule and changing my current rule to the following rule resolved my problem.

RewriteEngine on
RewriteCond %{HTTP_HOST} ^example\.com$
RewriteRule (.*) https://example.com/blog/ [R=301,L]

RewriteCond %{HTTP_HOST} ^www.example\.com$
RewriteRule (.*) https://example.com/blog/ [R=301,L]

Hope some one find this help full.

Try this:

RewriteEngine on
RewriteCond %{HTTP_HOST} ^example.com 
RewriteRule ^(.*)$ http://www.example.com/blog/$1 [L,R=301,NC]

Let me know if it works.