As it stands, Instagram only allows users to share one clickable link on their profile pages. Any links added to captions or comments are not clickable and must be copied and pasted in order to be accessed. There are some less effective workarounds available to users, but no way to reliably get a workable link anywhere but the profile page.
WHY DOESN’T INSTAGRAM ALLOW LINKS?
As frustrating as it is, Instagram has a very good reason for limiting linking. Once upon a time, users could include links in captions and comments. However, this function was heavily abused with link spamming in comments and frequent hacking and misusing of profiles. Instagram has taken a firm stance against excessive self-promotion.
IS THERE A WORKAROUND?
Yes and no. If you are an individual with a casual blog and no interest in spending money to get your link out there, you’ll need to settle for having your blog link on your profile.
If you’re concerned that your followers won’t know about the link unless they visit your profile page, include a call to action in your caption that directs them to your page to find your blog link. Obviously, this isn’t ideal because it requires a couple of steps from the follower, but it’s better than nothing.
You could also try to make it easier on your followers to copy and paste your link from your caption by making it a shortened URL. Sites like bitly.com or the Google URL shortener will turn long URLs into quick and easy links. Yes, your follower will still need to take the initiative, but a shorter link will look easier and more inviting.
WHAT ABOUT COMPANIES THAT PROMISE MORE?
Some companies like ilink promise to get working links into posts or Instagram bio that can support multiple links. This service is free. Ilink is typically marketed to companies that want the capability to support regular self-promotion without always purchasing Instagram ads.
FINE, HOW DO I ADVERTISE?
If you are interested in creating a linked advertisement, go to Instagram’s advertising page here. You can create single photo ads, carousel ads that scroll through large photos or multiple photos, or video ads. Click on the ad you want, and be directed to Facebook’s ad manager where you can pay for and schedule your ad.
source: https://il.ink/blog/social-media/how-to-add-links-on-instagram-posts/