[Edit separate layers after exporting]

Thank you so much for trying to help me. Unlock the background image does not help me. There is something that I am missing, I know it. I will try to "rasterise" see it that helps. Why is it so complicated in Affinity Photo. I have used this technique in other photo-editors and there were never any problems.
I do NOT want to change anything in the object, but be able to move them around (which is impossible), change the text (also impossible). 
I must do something very wrong, or .......
I am orchestral composer so I use Final Cut Pro X to make music videos, where Affinity Photo "should" play an important role in the creation of artistic material.
Thanks again. I will study your information and try again. I won't give up so easy.

[Edit separate layers after exporting]

Thanks. I put a screenshot. There are several objects here, each in separate layers. This is an .afphoto original file, but still not editable. It's just one single image!

[Edit separate layers after exporting]

HI. I am creating a background image with several objects (separate layers) for a Facebook group. Now, if I want to edit my creation one week later for example, on the separate layers, the separate layers are not there anymore!! I just can't edit. I have tried everything I can imagine.  During a couple of days I have tried different options like Export Persona, saving as a Affinity file etc. Nothing works. When I open it again everything is fixed together as one single image. 
It was so easy in Photoshop and in other photo editor software. I wished I knew about this before I bought the program. 
Can someone tell me how on earth I may be able to edit separate layers (separate objects like photos, text etc.) after I have saved or exported my creation.

I read that someone said that I have to save it as a Affinity file, but that does not work either.
I work on a MacPro. MacOS Catalina.
Please help. thanks.

[Creating a Signature]

Hey again.... I found the solution in Motion 5, that is a part of Final Cut Pro X video Editing Software. Everything is easy when you know how to do. By the way, I am a composer for video production of artist artwork so I'm happy I found Affinity Photo to create images I need in video projects.
I don't know if you ever have thought what you can do with simple images in a video project...... 

Thanks for all support from this forum.

[Creating a Signature]

Thank you so much for your answer. Now I know that Affinity can't create an animation movement that what I wanted in this case. The effect I would like to get is if someone writes with a pencil their handwritten signature. I will try in Motion 5, FCPXs powerful motion graphics tool. Thank you anyway. 
By the way, I guess you can get a similar effect if you "hide" the signature and move a layer slowly to the right.

Thanks.... Perhaps Affinity in the future will have animation features. That would be something to look forward to.
Have a nice day.

[Creating a Signature]

Hi. I am relatively new to Affinity, but I love the things you can do with it. I use a MacPro desktop computer and I take my photos with a Nikon D600. Now, how can you create a signature (your name for example) so it looks like the pen or pencil is writing the signature by hand. Perhaps I need the Motion 5 for that, but I would like to ask if there is a possibility i Affinity to create such a stunning composition. My wife is an artist (painter) and I would like to create her signature by a "living" handwritten composition. I have never seen this on any tutorial.
Thanks.