[Android Q&A, Help & Troubleshooting] yklaxds:
I can'’t get official recovery from ROM.

>adb push install-recovery.sh /data/local/tmp
16 KB/s (189 bytes in 0.010s)

>adb push recovery-from-boot.p /data/local/tmp
2211 KB/s (5506969 bytes in 2.431s)
>adb push recovery-resource.dat /data/local/tmp
3820 KB/s (4420149 bytes in 1.129s)

>adb push applypatch /data/local/tmp
2173 KB/s (53660 bytes in 0.024s)

>adb shell
HSSDM660QC:/ $ cd /data/local/tmp
HSSDM660QC:/data/local/tmp $
780332 68d9b4cfdc55d4d8d9b52a0fc4d672b235a4f108:recovery-from-boot.p <
patch boot.img: Supporting patching EMMC targets only.
1|HSSDM660QC:/data/local/tmp $ /data/local/tmp applypatch -b recovery-resource>
/system/bin/sh: /data/local/tmp: can't execute: Is a directory
126|HSSDM660QC:/data/local/tmp $ /data/local/tmp/applypatch -b recovery-resour>
/system/bin/sh: /data/local/tmp/applypatch: can't execute: Permission denied
126|HSSDM660QC:/data/local/tmp $ chmod 755 applypatch
c55d4d8d9b52a0fc4d672b235a4f108:recovery-from-boot.p <

applying patch to boot.img
failed to stat "recovery.img": No such file or directory
failed to statfs recovery.img: No such file or directory
target 20780332 bytes; free space -1 bytes; retry 1; enough 1
source inflation short by -4420149 bytes
applying patch failed; retrying
240414720 bytes free on /cache (13788456 needed)
failed to open "/cache/saved.file" for write: Permission denied
failed to back up source file
1|HSSDM660QC:/data/local/tmp $ ls
1E5E0A1D-6928-481B-A3A6-E782EEDB4F08.apk busybox install-recovery.sh
aapt busybox1 recovery-from-boot.p
applypatch busybox2 recovery-resource.dat
boot.img gzip
>adb shell <
/system/bin/sh: syntax error: unexpected '('
1|HSSDM660QC:/data/local/tmp $ HSSDM660QC:/ $ cd /data/local/tmp
/system/bin/sh: HSSDM660QC:/: not found
127|HSSDM660QC:/data/local/tmp $ HSSDM660QC:/data/local/tmp $
/system/bin/sh: HSSDM660QC:/data/local/tmp: not found
52a0fc4d672b235a4f108:recovery-from-boot.p < <
/system/bin/sh: syntax error: unexpected 'newline'
atch boot.img: Supporting patching EMMC targets only. <
1|HSSDM660QC:/data/local/tmp $ /data/local/tmp applypatch -b recovery-resource>
/system/bin/sh: /data/local/tmp: can't execute: Is a directory
126|HSSDM660QC:/data/local/tmp $ /data/local/tmp/applypatch -b recovery-resour>
/system/bin/sh: /data/local/tmp/applypatch: can't execute: Permission denied
126|HSSDM660QC:/data/local/tmp $ chmod 755 applypatch
c55d4d8d9b52a0fc4d672b235a4f108:recovery-from-boot.p <

applying patch to boot.img
failed to stat "recovery.img": No such file or directory
failed to statfs recovery.img: No such file or directory
target 20780332 bytes; free space -1 bytes; retry 1; enough 1
source inflation short by -4420149 bytes
applying patch failed; retrying
240414720 bytes free on /cache (13788456 needed)
failed to open "/cache/saved.file" for write: Permission denied
failed to back up source file
1|HSSDM660QC:/data/local/tmp $ ls
1E5E0A1D-6928-481B-A3A6-E782EEDB4F08.apk busybox install-recovery.sh
aapt busybox1 recovery-from-boot.p
applypatch busybox2 recovery-resource.dat
boot.img gzip
HSSDM660QC:/data/local/tmp $

It seems that need root that what I just don't have. And add my above files.

applypatch -b recovery-resource.dat boot.img recovery.img 694c5787c1a2bf7863f4daaec5f76b2799e43670 20780332 68d9b4cfdc55d4d8d9b52a0fc4d672b235a4f108:recovery-from-boot.p

https://drive.google.com/file/d/1xwuD5AEslIL3HcjUTLO8nsJQTnmC8V6B/view?usp=sharing