I´m replying to myself :)

I have never worked with Linux, so I search little bit and found this video: https://www.youtube.com/watch?v=T20jXu7rDCA
Based on it, I understood how to solve my problem.
I have edited evok.conf by nano text editor, where it is necessary to deleted all " ; " around [Extension 1]

root@M103_2-sn465:~# cd /etc root@M103_2-sn465:/etc# nano evok.conf GNU nano 2.7.4 File: evok.conf #!!! Do not use '#' for comments !!! [MAIN] ; !!! ALL MAIN SECTION OPTIONS ARE MANDATORY !!! config_version = 2.5 ; Configuration file version, DO NOT CHANGE! use_schema_verification = False ; Enabling this will deny any requests that do not match the JSON Schema; NO$ log_level = ERROR ; Minimum severity of messages to be logged; one of INFO, DEBUG, WAR$ log_file = /var/log/evok.log ; Log file to use; will be cleared on boot port = 8080 ; !!! Internal API port - only change if you are cer$ webhook_enabled = False ; Enables webhook notification - see e.g. https://sendgrid.com/blog/$ webhook_address = http://127.0.0.1:80 ; Put your server endpoint address here (e.g. http://123.123.123.123:/wh ) webhook_device_mask = ["input","wd"] ; List of device types to notify on (written as a JSON list) - adding AI will genera$ webhook_complex_events = False ; EVOK will send POST requests with the same data as WebSocket, rather than $ wifi_control_enabled = False ; !!! REQUIRES THE UNIPIAP WIFI CONTROLLER TO BE INSTALLED !!! Will allow ev$ soap_server_enabled = False ; Enables the simple SOAP server; use only if you need the functiona$ soap_server_port = 8081 ; !!! IF SOAP SERVER IS ENABLED, THIS PORT NEEDS TO BE UNIQUE (i.e. $ [NEURON_1] global_id = 1 ; Mandatory, REQUIRED TO BE UNIQUE allow_register_access = False ; Optional, False default scan_frequency = 10 ; Optional, 10 default, scanning frequency in [Hz] scan_enabled = True ; Optional, True default ; Below you can find examples for connecting devices over UART; first example is a Neuron extension while the second is a cu$ ; Devices sharing a port use the port settings of the first device on that port (baud rate, parity, stop bits) ; !!! Note that device_name has to match a filename in the /etc/hw_definitions directory !!! See /etc/hw_definitions/CUSTOM $ [EXTENSION_1] global_id = 2 ; Mandatory, REQUIRED TO BE UNIQUE device_name = xS10 ; Mandatory modbus_uart_port = /dev/extcomm/0/0 ; Mandatory neuron_uart_circuit = 1_01 ; Optional, allows associating extensions with specific Neuron UART-$ allow_register_access = True ; Optional, False default, is mandatory with third-party devices address = 1 ; Optional, 1 default scan_frequency = 10 ; Optional, 10 default, scanning frequency in [Hz] scan_enabled = True ; Optional, True default ; Note that the following settings will be inherited by other devices sharing the same port, i.e. /dev/extcomm/0/0 baud_rate = 19200 ; Optional, NEEDS UNIPI IMAGE TO WORK WITH UNIPI SERIAL PORT$ parity = N ; Optional, NEEDS UNIPI IMAGE TO WORK WITH UNIPI SER$ stop_bits = 1 ; Optional, NEEDS UNIPI IMAGE TO WORK WITH UNIPI SERIAL PORT$ ;[EXTENSION_2] ;global_id = 3 ; Mandatory, REQUIRED TO BE UNIQUE ;device_name = CUSTOM MODBUS DEVICE ; Mandatory ;modbus_uart_port = /dev/extcomm/0/0 ; Mandatory ;neuron_uart_circuit = 1_01 ; Optional, allows associating extensions with specific Neuron UART-$ ;allow_register_access = True ; Mandatory with third-party devices ;address = 1 ; Optional, 15 default ;scan_frequency = 2 ; Optional, 1 default, scanning frequency in [Hz] ;scan_enabled = True ; Optional, True default [OWBUS_1] owbus = /dev/i2c-1 --i2c=/dev/i2c-1:ALL ; Mandatory, scanned bus (--i2c=/dev/i2c-1:ALL or localhost:2122 or 'u' for USB dong$ interval = 3 ; Mandatory, [s] length of sensor reading scan_interval = 300 ; Mandatory, [s] How often the scanning is done ; See below for 1Wire extension module configuration ; Example for the 1W-4R/4DI extension module, 1W-8R is almost the same, only with inputs instead of relays ; ; - Map a new 1Wire sensor with the appropriate address, type and interval ; - The syntax can be either SENSOR or 1WDEVICE ; - Setting the correct reading interval is crucial to achieve ideal performance; the default interval is 15s ; [ Read 99 lines ] ^G Get Help ^O Write Out ^W Where Is ^K Cut Text ^J Justify ^C Cur Pos ^Y Prev Page M-\ First Line ^X Exit ^R Read File ^\ Replace ^U Uncut Text ^T To Spell ^_ Go To Line ^V Next Page M-/ Last Line

Than:

Ctrl o, Enter, Ctrl x reboot

After reboot , Evok and Modbus started correctly.