Question: Need to count in C# app, minutes in SLA to show in format : 

```
N working days, N working hours, N working minutes

```

current code show up only hours:minutes format:

```
TimeSpan spWorkMin = TimeSpan.FromMinutes(12534);
string workHours = string.Format("{0}:{1:00}", (int)spWorkMin.TotalHours, spWorkMin.Minutes);
Console.WriteLine(workHours);

```

Answer: 
Start Windows cmd and enter the command:

```
py -m pip install opcua

```
Looks like you didn't install opcua correctly.

Try to use `pip list` to check is it installed.

You can get examples from <https://github.com/FreeOpcUa/python-opcua>, and go to examples folder.

```
$ python server-minimal.py    

```

Open another terminal

```
$ python client-minimal.py

Objects node is:  Node(TwoByteNodeId(i=84))
Children of root are:  [Node(NumericNodeId(i=85)), Node(NumericNodeId(i=86)), 
Node(NumericNodeId(i=87))]
myvar is:  Node(NumericNodeId(ns=2;i=2))
myobj is:  Node(NumericNodeId(ns=2;i=1))

```

crypthography is just for security, it's not necessary to install.

If crypthography is not installed, you will get a message,

```
cryptography is not installed, use of crypto disabled

```