Sometimes you might not able to install the Astra theme via the WordPress dashboard. In such a case, try installing the theme via FTP.
Below are the detailed steps –
Step 1 – Download Astra theme’s zip from WordPress repository
Step 2 – Unzip the Astra theme zip file
Step 3 – Open your WordPress site via FTP. We would recommend you to use FileZilla
Step 4 – From FTP, visit the root of the WordPress install
Step 5 – Now visit wp-content folder > themes
Step 6 – Upload Astra unzipped file from step 2
Step 7 – Now the Astra is installed on your site. Go to WordPress Dashboard and activate it from Appearance > Themes