Hi Jae thanks for reaching out! Unfortunately what you are trying to do is not currently supported in Lucidchart. However we're always looking for ways to improve Lucidchart and your feedback is the best way for us to do that. Would you and anyone else interested in this feature mind adding your idea to our feature request form? Ideas submitted to this form are passed on to the product development team for their consideration. 

You can read more about the general restrictions of our mobile app in this help center article.