"it is indicated" is a correct and usable phrase in written English. You can use it to indicate that something was implied or suggested. For example, "It is indicated that the deadline for this project is tomorrow.".
Where necessary, it is indicated by arrows on charts.
It is indicated for mild to severe stages of Alzheimer's disease.
It is indicated in (11).
It is indicated by the green line.
It is indicated for larger defects.
It is indicated that OFQ is an anti-opiate substance.
It is indicated that all core samples have fractal structure.
Since I tried Ludwig back in 2017, I have been constantly using it in both editing and translation. Ever since, I suggest it to my translators at ProSciEditing.
Justyna Jupowicz-Kozak
CEO of Professional Science Editing for Scientists @ prosciediting.com