Can i set per-client hourly rate in Zoho Desk and not to correct the calculation on invoice?

Can i set per-client hourly rate in Zoho Desk and not to correct the calculation on invoice?

We use Zoho Desk to run one ticket per client per month. All time entries go to the ticket, we have to enter hourly rate manually and then correct it when we do the invoicing at the end of the month.
So, our workflow is as following:
I worked for 30 minutes, rate is $150. The invoice shows time entry as a quantity (which is always 1) and hourly rate is the actual amount.
When i have 20 entries in the ticket, i need to go and change it manually when run invoicing, which is a time waste.

see the screenshot for a sample. Is there a way to correct it and have specific rate assigned to a client and calculate the amounts showing actual rate and not the cost of the activity?