Transform conventional surveys to conversations which will lead to higher engagement. Try to collect feedback naturally, gain insights and make better decisions. So go for the Form Approach. But in a more interactive way. 

    Example: 

You go for a chat and provide a complete questionnaire where you plant the questions one by one

    Case1:

You : Hey John this Marie. Thanks for the subscription. Got a moment to share your thoughts...
John: Gladly
You: What are the top reasons that made you choose us(And you provide interactive buttons with prompt words and onclick() event you set the flag for the reply)

    Case2:

You: Good morning John. Got a few minutes?
John: Yes
You: Am taking feedback from everyone on our company culture...
	of the top of your head. how good is our company culture on a scale of 1 to 10 (And you provide buttons switch-case numbers for the reply)


Would suggect you not send him any links to go for a survey cause trust me people HATE IT. Try to make it interactive. Make a lot of combinations of questions ready with you with Rich Interface, buttons, checklists etc