To reset your security token in Salesforce, follow these steps:

1. Log in to your Salesforce account.
2. Click on your profile icon.
3. Select “Settings” from the dropdown menu.
4. In the left sidebar, under “My Personal Information,” click on “Reset My Security Token.”
5. Click the “Reset Security Token” button to generate a new security token.

If you are unable to find the “Reset My Security Token” option, please follow these steps:

Go to your User, click on the profile, Login IP Ranges and remove it. Reset you token and if it still necessary, add IP ranges back again

More info at Unable to see the Reset Security Token option