How to stop downloading .pdf in Iframe on phones?

Question

HTML

Link: _ jum.ee/gazovye-worky

<iframe src="http://adlab.ee/projects/7jum/kataloog.pdf"></iframe>

When you open the page on your phone, it starts automatically downloading the .pdf specified in the iframe.
1) how to stop downloading .pdf ?
2) how to make pdf in iframe displayed on mobile devices?
3) maybe there is another more convenient option for placing .pdf on the page?

Answer 1

1) don't embed pdf in src
2) use pdf.js: https://mozilla.github.io/pdf.js/
3) see p. 2