Hi, welcome to the forum.
We need a bit more information.
Are you working on a personal machine or in the Cloud?
Has R & Rstudio been working before and now you are suddenly getting the problem or is this a new installation?
Can you provide us with the code you are using?
Copy your code and paste it here between
```
```
Please also do the same with the output of
sessionInfo()
Here for general information are some guidelines on asking question on the forum FAQ Asking Questions](FAQ: How to do a minimal reproducible example ( reprex ) for beginners)