.htaccess for a domain and subdomain robots to prevent crawling - .htaccess

Question

domain.com - live server
dev.domain.com - dev server
Both with:
/public/robots.txt #which is for domain.com
/public/robots-dev.txt #which is for dev.domain.com
.htaccess
How to use the same .htaccess to select specific robots depending if it in live or dev?
I have tried this, but it is not working (part of the htaccess is to redirect non-https & www to https with non-www, please ignore that):
<IfModule mod_rewrite.c>
RewriteEngine On
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [L,NE,R=301]
RewriteRule ^(.*)$ public/$1 [L]
RewriteRule ^robots\.txt$ /robots-%1\.txt [L] #this one
</IfModule>
Update: Below is the public/.htaccess
# GLOBAL RULES
# ============
# Directories Index protection
Options -Indexes
# Remove index.php from URL
<IfModule mod_rewrite.c>
RewriteCond %{THE_REQUEST} ^GET.*index\.php [NC]
RewriteRule (.*?)index\.php/*(.*) /$1$2 [R=301,NE,L]
</IfModule>
# Default Apache rules
<IfModule mod_rewrite.c>
<IfModule mod_negotiation.c>
Options -MultiViews
</IfModule>
RewriteEngine On
# Redirect Trailing Slashes If Not A Folder...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^(.*)/$ /$1 [L,R=301]
# Handle Front Controller...
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME} !-f
RewriteRule ^ index.php [L]
# Handle Authorization Header
RewriteCond %{HTTP:Authorization} .
RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]
</IfModule>
# Robots.txt
RewriteRule ^(robots\.txt)$ /robots [NC,L]
# Iframe calling
<IfModule mod_headers.c>
Header unset X-Frame-Options
</IfModule>
# GTMetrix - Enable gzip compression
<IfModule mod_deflate.c>
# Compress HTML, CSS, JavaScript, Text, XML and fonts
AddOutputFilterByType DEFLATE application/javascript
AddOutputFilterByType DEFLATE application/rss+xml
AddOutputFilterByType DEFLATE application/vnd.ms-fontobject
AddOutputFilterByType DEFLATE application/x-font
AddOutputFilterByType DEFLATE application/x-font-opentype
AddOutputFilterByType DEFLATE application/x-font-otf
AddOutputFilterByType DEFLATE application/x-font-truetype
AddOutputFilterByType DEFLATE application/x-font-ttf
AddOutputFilterByType DEFLATE application/x-javascript
AddOutputFilterByType DEFLATE application/xhtml+xml
AddOutputFilterByType DEFLATE application/xml
AddOutputFilterByType DEFLATE application/json
AddOutputFilterByType DEFLATE font/opentype
AddOutputFilterByType DEFLATE font/otf
AddOutputFilterByType DEFLATE font/ttf
AddOutputFilterByType DEFLATE image/svg+xml
AddOutputFilterByType DEFLATE image/x-icon
AddOutputFilterByType DEFLATE text/css
AddOutputFilterByType DEFLATE text/html
AddOutputFilterByType DEFLATE text/javascript
AddOutputFilterByType DEFLATE text/plain
AddOutputFilterByType DEFLATE text/xml
# Remove browser bugs (only needed for really old browsers)
BrowserMatch ^Mozilla/4 gzip-only-text/html
BrowserMatch ^Mozilla/4\.0[678] no-gzip
BrowserMatch \bMSIE !no-gzip !gzip-only-text/html
Header append Vary User-Agent
</IfModule>
# GTMetrix - Enable gzip compression
# GTMetrix Browser Caching
<IfModule mod_expires.c>
ExpiresActive On
ExpiresByType image/jpg "access plus 1 week"
ExpiresByType image/jpeg "access plus 1 week"
ExpiresByType image/gif "access plus 1 week"
ExpiresByType image/png "access plus 1 week"
ExpiresByType image/svg "access plus 1 month"
ExpiresByType text/css "access plus 1 week"
ExpiresByType text/javascript "access plus 1 week"
ExpiresByType application/pdf "access plus 1 month"
ExpiresByType application/json "access plus 1 week"
ExpiresByType application/javascript "access plus 1 week"
ExpiresByType text/x-javascript "access plus 1 week"
ExpiresByType application/x-shockwave-flash "access plus 1 month"
ExpiresByType image/x-icon "access plus 1 year"
ExpiresDefault "access plus 1 month"
</IfModule>
# GTMetrix Browser Caching

Answer 1

You may use these rules:
RewriteEngine On
RewriteCond %{HTTPS} off [OR]
RewriteCond %{HTTP_HOST} ^www\. [NC]
RewriteCond %{HTTP_HOST} ^(?:www\.)?(.+)$ [NC]
RewriteRule ^ https://%1%{REQUEST_URI} [L,NE,R=301]
RewriteCond %{HTTP_HOST} ^dev\. [NC]
RewriteRule ^robots\.txt$ public/robots-dev.txt [L,NC]
RewriteRule ^(?!public/)(.*)$ public/$1 [L,NC]