In the future, please include some basic information. What desktop you are using is less than the minimum.
I think you are using KDE.
I also think your picture is specifically the “Network speed” widget that is already included with Plasma.
(note: you may need to adjust the settings for it to appear in your panel as shown in the photo)
If for whatever reason you need an alternative there is also this one on store.kde.org:
(and pling, and in the desktop widget installer, and in discover)
Network Bandwidth Monitor - Qt5 - pling.com