laravel

I have implemented the designer onespan iframe into our system. I am using laravel for doing this.  My question is regarding the sender authentication code which is a single use ? How can we implement creating a package and use the sender authentication code so that when the use clicks on a button it directly redirects them to the onespan designer iframe where he can add documents and procedd forward ? 

I have been using the rest api to create transactions for the signing ceremony. The api returns a token and the transaction id. I have built the url to open it in another browser tab and continue with the signing ceremony. I was wondering if is there a way to bypass the One Span UI and use my own UI for the signing ceremony? Using the branding of the company. Is it possible using the api or is it integrating some SDK? My stack is VueJS and Laravel.