how can I save files to Word 2007 and Excel 2007 using LO Version: 6.3.6.2

How can I save files to Word 2007 (NOT 365) and Excel 2007 (NOT 365) using LO Version: 6.3.6.2 ?

LO Version: 6.3.6.2
Build ID: 2196df99b074d8a661f4036fca8fa0cbfa33a497
CPU threads: 4; OS: Mac OS X 10.15.6; UI render: default; VCL: osx;
Locale: en-US (en_US.UTF-8); UI-Language: en-US
Calc: threaded

Never work in foreign file formats. Never store your important documents in a foreign (and/or obsolete) file format.
Always use the native, international standard (ISO) ODF file formats for your documents.

And at the end of editing you can save/export a copy of your important documents into the desired foreign file format - if it is necessary.

Note: There is not (never was and never will be) 100% compatibility between the different file formats. You always will lose some formatting property at every conversion. And an opening/saving procedure always means a kind of conversion, because the LibreOffice can work with an ODF model only.

There are third party extensions for the Munltiformat save. They can save the documents into more than one file formats in same time:

MultiFormatSave

MultiSave

(Of course there is export filter to the MS Office 2007 version OOXML files. Whereas the MS Office file types have many-many sub-(sub-(sub)) versions, therefore the LO 6.4.6 supports one version of the the OOXML (Word 2007-365), and one version of the binary (Word 97-2003) file format. The older LO versions can save into the more obsolete MS file formats too. Just use the Save as menu item, and choose the appropriate file version for a COPY of your document.)

Thank you.
Follow-up Q:
Will those using Microsoft Office be able to open the ODF files I email to them?

Yes, the newer MSO versions can open the ODF 1.1(?) version documents. But the conversion NEVER will be perfect nor flawless, and the MSO can not save into the standard (ISO/IEC 26300) ODF file format.
If you must use exclusively the MSO formats, then you must buy a MS Office.

Thanks, Zizi64.
No, I do not need to use exclusively the MSO formats. I just want to be able to send my LO-created files that others can edit and return to me. Recently, a few recipients have had difficulty opening LO-created files saved in MS formats, partially related, I think, to a lock file missing situation.
If my recipients can open my ODF files, edit and save them in MS, and return the edited files to me, I should be able to open the edited files in LO.
The files in question are working files, so they do not need to be perfect/flawless at this stage.
I do not want to use Google docs or other cloud solutions.
Any additional advice welcomed.
Thank you.

“If my recipients can open my ODF files, edit and save them in MS, and return the edited files to me, I should be able to open the edited files in LO.”

It is a very bad practice to convert to/back between the different file types.

The LibreOffice is FREE for everybody.

Got it… Thanks.

If you need to interoperate with people using other software, ans thus convert data when sending (which is frequent when LibreOffice has better conversion tools than the other software - i.e., practically always; e.g., MS Office converts both from and to ODF much worse than LibreOffice does from/to OOXML, although still not perfectly): always keep your data in native format (ODF in this case), and create a converted copy for sending purposes only. When you have received the response with edits, copy the edits into your native original, discarding any formatting of the received file (paste only text). This will allow you to keep your work safe of conversion problems.

Thanks - much appreciated

You might want to try my extension (change the file name extension to .oxt to install):

https://ask.libreoffice.org/upfiles/15979113741389674.odt

Unlike Multisave, my extension does not call up a dialog, you simply click on a button, and it will automatically save ODT/ODS/ODP to DOC/XLS/PPT or DOCX/XLSX/PPTX (depending on the button that you use).