In order to use Ahrefs, you will need a subscription which allows you to pull data from their API. You then just need to navigate to ‘Configuration > API Access > Ahrefs’ and then click on the ‘generate an API access token’ link.
You will then be taken to Ahrefs, where you need to ‘allow’ access to the Screaming Frog SEO Spider.
You will then be given a unique access token from Ahrefs (but hosted on the Screaming Frog domain).
Copy and input this token into the API key box in the Ahrefs window, and click ‘connect’ –
You can then select the metrics you wish to pull at either URL, subdomain or domain level.
Then simply click ‘start’ to perform your crawl, and the data will be automatically pulled via their API, and can be viewed under the ‘link metrics’ and ‘internal’ tabs.