Currency rate translation in TS01

Hi Experts,

We have a custom program to create security transactions. But when executing the custom program, rate is always defaulted to 'Exchange Rate Fixed' radio button as seen below. We want this to be in 'Current Rate' instead.

So to check, I manually created a security transaction in TS01, but as per manual creation, currency translation is still defaulted to 'Exchange Rate Fixed'.

My question is where can I set the default to 'Current Rate' instead of 'Exchange Rate Fixed'?

Any input will be highly appreciated.

Thank you!

Regards,

Katherine Darunday