Hello there, 

I bought the pro version, and seeking for help

I am trying to embed the following page 

https://funkidviolin.com/aplayalong/aplayertab.php?&m=1&ukulele-Twinkle_Twinkle_Little_Star  

into the a page under the same domain which is this one https://funkidviolin.com/how-to-play-twinkle-little-star-on-lego-ukulele-free-interactive-music-sheet/

using this piece this code 

[advanced_iframe width="100%" src="https://funkidviolin.com/aplayalong/aplayertab.php?&m=1&ukulele-Twinkle_Twinkle_Little_Star" fullscreen_button="top_left"]

Based the error throwed, it seems it is the same origin issue. but I used your FREE IFRAME CHECKER 3.0, it works perfectly. 

I also tried [iframe] short code, it does work too. 

Could you please advise me the issues, thank you very much