When referring to the homepage, a trailing slash after the hostname is optional since it leads to the same content ("https://example.com/" is the same as "https://example.com"). For the path and filename, a trailing slash would be seen as a different URL (signaling either a file or a directory), for example, "https://example.com/fish" is not the same as "https://example.com/fish/".
But I'm not talking about any kind of link building. I'm talking about organic link building by getting out there and creating insatiable "anchor content" on your website, then linking to that content with equally-great content that's created on authority sites like Medium, Quora, LinkedIn and other publishing platforms. It's not easy by any measure. Google is far more wary of newcomers these days than it once used to be.
Testimonials. If case studies aren't a good fit for your business, having short testimonials around your website is a good alternative. For B2C brands, think of testimonials a little more loosely. If you're a clothing brand, these might take the form of photos of how other people styled a shirt or dress, pulled from a branded hashtag where people can contribute.