If this hasn’t been solved yet: You could try using Cloudflare. Cloudflare will block lots of spam such as DoS/DDoS attacks. It also has a Firewall you can set manually, so if you know the IP addresses of the bot(s) you can just block them without them even touching your servers.

You can set up firewall applications on your server as well, but using Cloudflare will let their servers take the brunt of the attack, so it never even reaches you.

If you’re set on the IP changing, you need to switch regions to do that (even just switching from NYC3 to NYC2, for example), or else you’ll just get the same IP under normal circumstances. Read: https://www.digitalocean.com/community/tutorials/how-to-migrate-digitalocean-snapshots-between-regions

Hi you can block the bots From Apache2 /etc/apache2/sites-available/default
Below I mentioned

<Directory /var/www/html>
        #Header set Access-Control-Allow-Origin "*"
        BrowserMatchNoCase "Baiduspider" bots
        BrowserMatchNoCase "HTTrack" bots
        BrowserMatchNoCase "Yandex"  bots
        BrowserMatchNoCase "AhrefsBot" bots
        BrowserMatchNoCase "exabot"  bots
        BrowserMatchNoCase "MJ12bot" bots
        BrowserMatchNoCase "dotbot"  bots
        BrowserMatchNoCase "gigabot" bots
        BrowserMatchNoCase "Visbot" bots
        BrowserMatchNoCase "SemrushBot" bots
        BrowserMatchNoCase "SpammerRobot" bots
        BrowserMatchNoCase "SecurityHoleRobot" bots

        Options Indexes FollowSymLinks

        AllowOverride none
        Order allow,deny
        Allow from all
        Deny from env=bots
        Require all granted