My query is can we create a webhook which would dynamically import the data (let say a lead's email address) from Marketo database and post it into my Marketo custom object field (let say custom email address) when he/she fills out a form?
If you have a webhook-compatible service that could do that for you, then I don't see a reason why you can't do that (Sandy's Flowboost would be a great fit here IMO)! Basically, you'd want to pass the necessary lead info along with the necessary data for creating a custom object record from Marketo to the service which can then call Marketo's CO APIs to create a CO record. The service would need to make multiple calls to Marketo to get an access token (in case the previously cached token isn't valid) and then to create a custom object record. Additionally, it'd be a good idea to save all values from the form post to a single field and then pass it to the service! Check out Sandy's article regarding that here.
HI @Darshil_Shah1 , thanks for your response. Just to let you know that I played to post the data (Custom email address, custom id) via "import custom object data" in my defined custom object and it worked well.
However, I was actually trying to figure it out if we can somehow do this via automation (like webhook etc) where the custom object record gets created (and custom fields with values) and mapped with the correct lead id when a form fillout happens.
But as you mentioned, it requires a webhook compatible service to get the job done and cannot be achieved via Marketo itself.
Not something that could be done via Marketo UI only! However, this is doable using webhook and would require some development effort. You can call the webhook from the trigger campaign that listens for the form-fill activity.