Courses are updatd by the Scheduler (CRON) settings when any user logs in to the site.
The source of receiving courses can be customized for each of the destinations.

Sources:
1) Central Bank of the Russian Federation
2) European Central Bank
3) National Bank of Ukraine
4) National Bank of Kazakhstan
5) National Bank of the Republic of Belarus
6) Privat 24 (Ukraine)
7) exmo.me
8) bitfinex.com
9) yobit.net
10) bitstamp.net
11) binance.com
12) coinbase.com
13) hitbtc.com
14) poloniex.com
15) bitexbook.com
16) cryptocompare.com
17) okcoin.com
18) grinex.io
19) cryptonex.org
20) okx.com
21) bitpay.com
22) bitmart.com
23) blockchain.com
24) bitdelta.com
25) rapira.net
26) heleket.com
27) bybit.com
28) whitebit.com
29) Sources can be added independently

Which site is chosen to receive courses, from which we get the course. The average trading rate is taken.
You can update the courses manually by clicking on the link Update Courses.
Courses will be updated if the Do not update option is not selected for the selected course.
The date of course change is displayed in the list of courses Info - Date of change.

Additional settings
Commission - commission of the exchange bureau for this direction.
Neg. (Negative?) - downgrade game (for example, if you have an excess of some currency and you can give it cheaper than the current rate, or you just need a rate that should be lower than the existing one). 
If the checkbox is checked, the commission of the exchange office will work as a bonus.
Example:
Direction - WebMoney WMZ => WebMoney WMR
Exchange rate - 34.3681 (I would like to have it already).
Commission - 0.5% (0.1718405) (math: 34.3681 * 0.5 / 100).
Final rate - 34.3681 - 0.1718405 = 34.1962595 (rounding 34.19626).
Check the checkbox "Negative". (Negative?)
Final rate - 34.3681 + 0.1718405 = 34.5399405 (rounding 34.53994).
Commission of the payment system is not taken into account in this calculation.
Min. commission is the amount of the minimum commission of the exchange bureau. 
Regardless of the exchange amount, the commission of the exchange bureau will not be lower than the specified number.
Max. commission - the sum of the maximum commission of the exchange bureau. 
Limit of the exchange bureau commission amount. If 0, the commission is not limited.
Min. amount to exchange - it is impossible to execute an application less than the entered amount.
Max. amount to exchange - not filled in or 0, the maximum amount to exchange is limited by the stock (reserve) of the outgoing currency.
I.e. the currency that the user will receive.

Settings of exchange types by direction
Operator processing - the checkbox for directions is checked = the operator processing type is active for this direction.
Semi-automatic - the checkbox for directions is checked = the semi-automatic type is active for this direction.
Available if the incoming currency has API connected.
Automatic - the checkbox for directions is checked = automatic type is active for this direction.
Available if both currencies have APIs connected.

Restrictions on directions
Active - status of the direction. Unchecked, the direction will be disabled.
It is necessary to monitor the conditions of each of the payment systems and fulfill the restrictions.
If one of the payment systems prohibits the exchange to another payment system, it is necessary to disable this direction.

Information
Rate updated - the date of the last rate update for the direction.
Change date - the date of the last change of any other course data. It is changed for all courses.
Operator - login of the administrator who performed the last operations with the directions.