I do have a question, Can I use I the work I am producing mainly artworks and design, in portfolio/website with getting any approval from the clients?
Yes, that is correct. It is always best to check this with your client. As long as your clients agree that you can use the artworks/design you have completed for their project, you can add these to your portfolio. If the portfolio is from a past Upwork project, you can link the portfolio to the project. These items will be displayed more prominently and help build your credibility in the marketplace. We’ll automatically email the client when a portfolio item has been linked, giving them three days to reject it before the item is publicly linked to your profile.