It is impossible to create bank account token without routing_number, even if it is marked as optional and country-specific, and there is no routing_number in some countries (for example in Singapore).
any
How can we get bank account token without this parameter?
In stripe/stripe's document to create bank account token routing number is given as an optional, but we can't leave it as optional.
To solve that issue I research some bank related sites and find one solution.
The Routing number is a 7 digit number which is a combination of Bank code and Branch code.
Bank code is 4 digit number and Branch code is 3 digit number. By combine that two respected number we can make routing number.
Parameter to pass in createTokenWithBankAccount method
let params = {
accountNumber: this.state.accountNo,
countryCode: 'sg',
currency: 'sgd',
routingNumber: `${this.state.bankCode}${this.state.branchCode}`
};
I design Payment screen as under

Hey @paynd – if you're having trouble with your integration, we suggest sending an email describing your issue to [email protected] . They'll be happy to help :)
Thank you @bg-stripe!
Most helpful comment
In stripe/stripe's document to create bank account token routing number is given as an optional, but we can't leave it as optional.
To solve that issue I research some bank related sites and find one solution.
The Routing number is a 7 digit number which is a combination of Bank code and Branch code.
Bank code is 4 digit number and Branch code is 3 digit number. By combine that two respected number we can make routing number.
Parameter to pass in createTokenWithBankAccount method
I design Payment screen as under