A. Check the app settings for call preferences. Look for options related to SIM management or call settings. If there is an option to select which SIM to use for calls, set it to your non-Turkcell SIM.
B. If the app does not support this feature, consider using your device's built-in call settings to manage which SIM is used for calls. Go to Settings > Network & internet > SIM cards, and adjust the default SIM for calls.