не могу сделать перенос сайта сделанный на october cms

Разве index.php может скачиваться если сервер настроен правильно? Ведь для сервера это исполняемый файл. Ищите проблему в настройках openserver 6 - в каталоге проекта .osp в файле project.ini что написано? Версию октября смотрите в composer.json

в .htaccess длжно быть так

<IfModule mod_rewrite.c>

    <IfModule mod_negotiation.c>
        Options -MultiViews
    </IfModule>

    RewriteEngine On

    ##
    ## You may need to uncomment the following line for some hosting environments,
    ## if you have installed to a subdirectory, enter the name here also.
    ##
    # RewriteBase /

    ##
    ## Uncomment following lines to force HTTPS.
    ##
    # RewriteCond %{HTTPS} off
    # RewriteRule (.*) https://%{SERVER_NAME}/$1 [L,R=301]

    ##
    ## Uncomment to redirect trailing slashes in URLs.
    ##
    # RewriteCond %{REQUEST_FILENAME} !-d
    # RewriteRule ^(.*)/$ /$1 [L,R=301]

    ##
    ## Uncomment to redirect /index.php/path to /path
    ##
    # RewriteRule ^index\.php/(.*)$ /$1 [L,R=301]

    ##
    ## Handle Authorization Header
    ##
    RewriteCond %{HTTP:Authorization} .
    RewriteRule .* - [E=HTTP_AUTHORIZATION:%{HTTP:Authorization}]

    ##
    ## Blocked folders
    ##
    RewriteRule ^bootstrap/.* index.php [L,NC]
    RewriteRule ^config/.* index.php [L,NC]
    RewriteRule ^vendor/.* index.php [L,NC]
    RewriteRule ^storage/cms/.* index.php [L,NC]
    RewriteRule ^storage/logs/.* index.php [L,NC]
    RewriteRule ^storage/framework/.* index.php [L,NC]
    RewriteRule ^storage/temp/protected/.* index.php [L,NC]
    RewriteRule ^storage/app/uploads/protected/.* index.php [L,NC]

    ##
    ## Allowed folders
    ##
    RewriteCond %{REQUEST_FILENAME} -f
    RewriteCond %{REQUEST_FILENAME} !/.well-known/*
    RewriteCond %{REQUEST_FILENAME} !/app/(assets|resources)/.*
    RewriteCond %{REQUEST_FILENAME} !/storage/app/media/.*
    RewriteCond %{REQUEST_FILENAME} !/storage/app/resources/.*
    RewriteCond %{REQUEST_FILENAME} !/storage/app/uploads/public/.*
    RewriteCond %{REQUEST_FILENAME} !/storage/temp/public/.*
    RewriteCond %{REQUEST_FILENAME} !/themes/.*/(assets|resources)/.*
    RewriteCond %{REQUEST_FILENAME} !/plugins/.*/(assets|resources)/.*
    RewriteCond %{REQUEST_FILENAME} !/modules/.*/(assets|resources)/.*
    RewriteRule !^index.php index.php [L,NC]

    # RewriteRule ^robots.txt - [L]
    # RewriteRule ^phpinfo.php - [L]
    # RewriteRule ^p.php - [L]

    ##
    ## Block all PHP files, except index
    ##
    RewriteCond %{REQUEST_FILENAME} -f
    RewriteCond %{REQUEST_FILENAME} \.php$
    RewriteRule !^index.php index.php [L,NC]

    ##
    ## Standard routes
    ##
    RewriteCond %{REQUEST_FILENAME} !-f
    RewriteRule ^ index.php [L]

</IfModule>

.env

APP_NAME="October CMS"
APP_ENV=local
APP_KEY=твой ключ
APP_DEBUG=true
APP_URL=твой домен
APP_LOCALE=ru

ACTIVE_THEME=тема из каталога themes проекта с которой сайт загружается
BACKEND_URI=adminpiter
CMS_ROUTE_CACHE=false
CMS_ASSET_CACHE=false
LINK_POLICY=detect
DEFAULT_FILE_MASK=775
DEFAULT_FOLDER_MASK=775

DB_CONNECTION=mysql
DB_HOST="имя модуля базы данных используемый в 6 OSPanel - НЕ localhost!!!!! " 
DB_PORT=3306
DB_DATABASE="имя базы"
DB_USERNAME="юзер базы"
DB_PASSWORD="пароль юзера базы"

LOG_CHANNEL=single
BROADCAST_DRIVER=log
CACHE_DRIVER=file
QUEUE_CONNECTION=sync
SESSION_DRIVER=file
SESSION_LIFETIME=120

REDIS_HOST=127.0.0.1
REDIS_PASSWORD=null
REDIS_PORT=6379

MAIL_MAILER=log
MAIL_HOST=null
MAIL_PORT=null
MAIL_USERNAME=null
MAIL_PASSWORD=null
MAIL_ENCRYPTION=null
MAIL_FROM_ADDRESS=noreply@octobercms.tld
MAIL_FROM_NAME="${APP_NAME}"

AWS_ACCESS_KEY_ID=
AWS_SECRET_ACCESS_KEY=
AWS_DEFAULT_REGION=us-east-1
AWS_BUCKET=