Most video or slideshow platform now offer the possibility to insert featured videos or slideshow into your web or blog pages.
To do that, they give you an "embed" code to copy where you want the element to be inserted in the page. In fact, the element stays on the platform server but the code allows to display it into your page.
On Slideshare for instance, this code is visible next to the slideshow:

Select and copy this code. Here is how it looks like:

Well, you don't have to understand it all ...
To insert it into RedGrove, open a chapter and add a new page

The test editor appears and you have to click ont the "SOURCE" button in the upper left hand corner

Then copy code into the window and click "OK" and ... voilà!
Optional : take out the links
It is quite usual for platforms to add links back to their platform (do not ask me why, I don't have the slighest clue!)
It is possible to take out these links by deleting all code conteined between the "a" and "/a" tags that you can see highlighted here:

I have to admit, it's a bit like a treasure hunt for beginners but if it can allow to offer more clarity to the content ...
You turn to try ...
If you have some difficulties, don't hesitate to come back here and continue this discussion ...