up to now I can do only second one, and unfortunately it doesn't work
Is your SD-card new and have you tested it? -> h2testw_1.4 (Do not run endless verify.)
If your SC-card tests with errors, is significantly smaller than the labeled size, or is a no name generic, get a new one. (San-Disk, Samsung, etc.) 16GB is fine and SD-cards with the A1 specification are preferred.
For a guide to testing SD-Cards and flashing an OMV image, look -> here starting on page 24.
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Also, a wired Ethernet connection to the internet is needed to update and finalize the setup.