Where can I find kelp?

Could you please assist me in locating kelp? I'm having difficulty finding it and would greatly appreciate any information you might have. Is it possible to purchase kelp in supermarkets or specialty stores? Or perhaps there are certain online retailers that sell kelp? Additionally, are there any natural habitats or coastal areas where kelp grows abundantly and can be harvested? I'm particularly interested in fresh kelp, but dried options are also acceptable. Thank you in advance for your help in this matter.