In principle, the following applies: If a Dienstrad is provided and a salary conversion is agreed in this context, a non-cash benefit must be taxed for private use.
In the past, a flat rate of 0.5% of the gross list price was applied for this, analogous to the company car. Since January 14, 2020, this assessment value has been further reduced so that you now only have to pay tax on 0.25% of the gross list price.