It depends on the contents of your online bank statements and what they look like. If they have the logo of the bank, contact numbers, address and email id of the bank and contain details such as your account number, date of account opening etc, they're good enough.
If not, then it's best to get printouts of your statements and get them stamped, signed and dated by a bank official.
Additionally, get a letter/bank certificate from your bank in the format required by IRCC if you can.
Good luck.