shopify.toast is undefined when load url to ui-modal src

[Andn]

Hi.

I'm having a problem about "shopify.toast" when loading on ui-modal src.

I'm making a page with shopify bridge so I want to display the message with "shopify.toast". When I load the page without iframe ui-modal, "shopify.toast" is working. But when I load the page to src of ui-modal, the "shopify.toast" is undefined. I don't know why? Anyone has a problem like me? Please help me to resolve the problem?