To make the BNBForms booking widget appear on the individual site page, you can embed it as an iFrame.
<iframe src="https://bnbforms.com/100112/" height="1000" style="width:100%;border:0;"></iframe>
To find the code for embedding, go to your BNBForms dashboard > Widget Script scroll down to “3. You can alternately embed booking widget on a single page” and copy the code.
Then go to your website and paste this code to the page. A typical website builder will have a Code / iFrame / HTML block / widget for rendering the BNBForms code. For example: