These workarounds are fully comaptible with Virtuemart and you don't need extra extension to use it. It is a built in feature in Virtuemart.
By link or button
With the following code there will be 2 products added to the Virtumart cart automatically.
Product IDs: 316, 314 - This code should be copied and pasted into your content where you want to display your offer.
https://example.com/index.php?option=com_virtuemart&view=cart&task=add&virtuemart_product_id[]=316&quantity[]=1&virtuemart_product_id[]=314&quantity[]=1
Changing the quantity
You can define how many products you want to add by modifying the "&quantity[]=1" part:
&quantity[]=15
If you are using AWO Coupon you can add the coupon with the same click by adding the following line:
In this case the summer20off is the coupon code you share with your customers, you don't need coupon IDs.
&addcoupontocart=summer20off
Using it as a link for a special offer/bundle
You can put the link anywhere, like into Joomla content, newsletters, Fb posts etc.
<a href="https://example.com/index.php?option=com_virtuemart&view=cart&task=add&virtuemart_product_id[]=316&quantity[]=1&virtuemart_product_id[]=314&quantity[]=1">Check out our special deal</a>
To use as a button just simply add the following class to your link:
class="button"
By html form
In case you want to use a form you can copy and paste the following code:
<form method="post"/>
<input class="button" title="Add to Cart" type="submit" name="addtocart" value="Add to Cart"/>
<input type="hidden" name="option" value="com_virtuemart"/>
<input type="hidden" name="view" value="cart"/>
<input type="hidden" name="task" value="add"/>
<input type="hidden" name="virtuemart_product_id[]" value="316"/>
<input type="hidden" name="quantity[]" value="1"/>
<input type="hidden" name="virtuemart_product_id[]" value="314"/>
<input type="hidden" name="quantity[]" value="2"/>
</form>
There are some tricks how you can improve user experience for using this kind of addtocart feature in Virtuemart.