I worked as a per diem health worker. I didn't receive a form from my employer for this. Is there supposed to be a form or should I add it from my bank statements?

No, there is no form and you do not add it from your bank account.

Per diem payments are not considered wages—and are therefore non-taxable—as long as they meet certain conditions. You will be subject to taxes if any of the following are true: Payment is more than the allowable federal per diem rate. You did not file an expense report with your employer

 

 

Googling for:
How are per diem employees taxed?

returns:

Per diem payments are not considered wages—and are therefore non-taxable—as long as they meet certain conditions. 

Also see:

https://www.taxslayerpro.com/blog/post/per-diem-tax

 

Is this a reimbursement of expenses or is this income from your job?  If it is a reimbursement, follow the advice from @Leonard Smith. If this is income, see below.

 

Your per diems should have either been on Form W-2 or 1099-NEC if the persons you are working for do not consider you an employee. 

 

Enter your self-employment income on Schedule C.

 

Follow these steps to go to the Schedule C section of your return:

 

On the top right corner of TurboTax online screen, click on Search (or for CD/downloaded TurboTax locate the search box in the upper right corner).

1. Type in “schedule c” (or for CD/downloaded TurboTax, click Find).
2. Click on “Jump to schedule c”.
3. Click on the blue “Jump to schedule c” link