How to rotate labels in Power BI?

PowerBI does not let you override the label orientation but rather adjusts it based on the space you allocate to the visual. Try making your visual a bit wider. For long labels, increase the maximum size of the X Axis on the settings to give more space to the labels and less to the bars. You can also tweak the padding and width settings to eek out a little more space. Also, consider abbreviating long labels.

I went through the same issue/requirement but found no available configuration option for X axis labels. Labels are adjusted automatically based on number of BAR and width of the chart. Anyway, you can look on different options under "X-Axis" after changing the Type to "Categorical" as shown below-

Under the x-axis switch on the concatenated label. THis should do the trick for you