value and content
According to the specifications, the correct attribute for directives is content, but Google does in fact honor the attribute value as well, which is a common attribute in meta tags as well. If both, content and value, are set Google will prefer content. Consider the following example:
<meta name="robots" value="noindex, follow" content="index, follow" />
Google Search Console URL Inspection will declare this URL can be indexed which is in line with the specifications.