Can't we have dynamic checkbox?

Can't we have dynamic checkbox? I have a requirement where there is a list of family members for a particular Unique Code and checkbox should get populated with that list. Is this possible?

Have you already created a form where fields must be populated? If so, can you please share so we checked it? In general, checkboxes and text entries are supported to be populated with Spreadsheet to Form widget. 

Yes, here is the link

https://form.jotform.me/aensharjah/izan

Here is the flow.

1. Are you a Sharjah Sabil Holder? -> Select Yes

2. Enter 3481 in the HOF Sabil ID Text Field and click Show Members

3. Scroll below, there is HOF & Dependants text area which gets populated.

My question, instead of this Text Area can it be populated as checkboxes?

You can add the checkbox field HOF & Dependants with options "30387060 Bhai Burhanuddin M Yusuf Companywala" and "30387060 Bahen Jamila Burhanuddin Companywala" and select them when 3481 code is entered. 

It is now possible to dynamically change the checkbox options based on the entered code.

How to Use the Spreadsheet to Form Widget

But I have to create check box having "30387060 Bhai Burhanuddin M Yusuf Companywala" & "30387060 Bahen Jamila Burhanuddin Companywala" options right?

There are 4350 records, I cannot create 4350 checkboxes :)?

3481 is the Head of Family,

30387060 Bhai Burhanuddin M Yusuf Companywala

30387060 Bahen Jamila Burhanuddin Companywala

these both are his dependants.

Similarly, if you enter 422, you will get the following results.

1. 20353255 Mulla Taha Shabbar Hussain

2. 50496575 Bahen Yasmeen

3. 50496576 Bhai Murtaza

4. 60415364 Bahen Husaina

Can you help me with this?

Yes, you would have to create checkbox having those options. 

However, the checkbox field is limited to ~ 65,000 character, so you will not be able to add 4350 options. 

I would suggest you to continue using the Text Area field.